arm: move CONFIG_PREBOOT="usb start" to KConfig

This commit moves CONFIG_PREBOOT="usb start" to common/KConfig
for all boards also declaring USB_KEYBOARD.

Besides simplifying defconfig files, this also enables support for
board-specific CONFIG_PREBOOT for sunxi boards:
commit 37304aaf

 ("Convert CONFIG_USE_PREBOOT and CONFIG_PREBOOT to
Kconfig") intended to support CONFIG_PREBOOT, but
include/configs/sunxi-common.h hardcodes preboot as part of internally
defined CONSOLE_STDIN_SETTINGS, silently ignoring any board-specific
CONFIG_PREBOOT.
Signed-off-by: Jonas Smedegaard <dr@jones.dk>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Series-Cc: Jagan Teki <jagan@amarulasolutions.com>
Series-Cc: Lukasz Majewski <lukma@denx.de>
Series-Cc: Andre Przywara <andre.przywara@arm.com>

common/Kconfig

@@ -403,6 +403,7 @@ config BOOTCOMMAND
 
 config USE_PREBOOT
 	bool "Enable preboot"
+	default "usb start" if USB_KEYBOARD
 	help
 	  When this option is enabled, the existence of the environment
 	  variable "preboot" will be checked immediately before starting the

configs/libretech-ac_defconfig

@@ -15,7 +15,6 @@ CONFIG_DEFAULT_DEVICE_TREE="meson-gxl-s805x-libretech-ac"
 CONFIG_DEBUG_UART=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="usb start"
 CONFIG_MISC_INIT_R=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set

configs/libretech-s905d-pc_defconfig

@@ -15,7 +15,6 @@ CONFIG_DEFAULT_DEVICE_TREE="meson-gxl-s905d-libretech-pc"
 CONFIG_DEBUG_UART=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="usb start"
 CONFIG_MISC_INIT_R=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_CMD_BDI is not set

configs/libretech-s912-pc_defconfig

@@ -14,7 +14,6 @@ CONFIG_DEFAULT_DEVICE_TREE="meson-gxm-s912-libretech-pc"
 CONFIG_DEBUG_UART=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="usb start"
 CONFIG_MISC_INIT_R=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_CMD_BDI is not set

configs/pinebook-pro-rk3399_defconfig

@@ -13,7 +13,6 @@ CONFIG_DEFAULT_DEVICE_TREE="rk3399-pinebook-pro"
 CONFIG_DEBUG_UART=y
 CONFIG_BOOTDELAY=3
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="usb start"
 CONFIG_DEFAULT_FDT_FILE="rockchip/rk3399-pinebook-pro.dtb"
 CONFIG_MISC_INIT_R=y
 CONFIG_DISPLAY_BOARDINFO_LATE=y

configs/rockpro64-rk3399_defconfig

@@ -13,7 +13,6 @@ CONFIG_SPL_SPI_SUPPORT=y
 CONFIG_DEFAULT_DEVICE_TREE="rk3399-rockpro64"
 CONFIG_DEBUG_UART=y
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="usb start"
 CONFIG_DEFAULT_FDT_FILE="rockchip/rk3399-rockpro64.dtb"
 CONFIG_MISC_INIT_R=y
 CONFIG_DISPLAY_BOARDINFO_LATE=y

configs/rpi_0_w_defconfig

@@ -9,7 +9,6 @@ CONFIG_DEFAULT_DEVICE_TREE="bcm2835-rpi-zero-w"
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="usb start"
 CONFIG_MISC_INIT_R=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set

configs/rpi_2_defconfig

@@ -9,7 +9,6 @@ CONFIG_DEFAULT_DEVICE_TREE="bcm2836-rpi-2-b"
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="usb start"
 CONFIG_MISC_INIT_R=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set

configs/rpi_3_32b_defconfig

@@ -10,7 +10,6 @@ CONFIG_DEFAULT_DEVICE_TREE="bcm2837-rpi-3-b"
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="usb start"
 CONFIG_MISC_INIT_R=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set

configs/rpi_3_b_plus_defconfig

@@ -10,7 +10,6 @@ CONFIG_DEFAULT_DEVICE_TREE="bcm2837-rpi-3-b-plus"
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="usb start"
 CONFIG_MISC_INIT_R=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set

configs/rpi_3_defconfig

@@ -10,7 +10,6 @@ CONFIG_DEFAULT_DEVICE_TREE="bcm2837-rpi-3-b"
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="usb start"
 CONFIG_MISC_INIT_R=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set

configs/rpi_defconfig

@@ -9,7 +9,6 @@ CONFIG_DEFAULT_DEVICE_TREE="bcm2835-rpi-b"
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="usb start"
 CONFIG_MISC_INIT_R=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set

configs/seaboard_defconfig

@@ -10,7 +10,6 @@ CONFIG_TARGET_SEABOARD=y
 CONFIG_DEFAULT_DEVICE_TREE="tegra20-seaboard"
 CONFIG_OF_SYSTEM_SETUP=y
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="usb start"
 CONFIG_SYS_PROMPT="Tegra20 (SeaBoard) # "
 # CONFIG_CMD_IMI is not set
 # CONFIG_CMD_FLASH is not set

configs/ventana_defconfig

@@ -10,7 +10,6 @@ CONFIG_TARGET_VENTANA=y
 CONFIG_DEFAULT_DEVICE_TREE="tegra20-ventana"
 CONFIG_OF_SYSTEM_SETUP=y
 CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="usb start"
 CONFIG_SYS_PROMPT="Tegra20 (Ventana) # "
 # CONFIG_CMD_IMI is not set
 CONFIG_CMD_GPIO=y

include/configs/sunxi-common.h

@@ -425,7 +425,6 @@ extern int soft_i2c_gpio_scl;
 
 #ifdef CONFIG_USB_KEYBOARD
 #define CONSOLE_STDIN_SETTINGS \
-	"preboot=usb start\0" \
 	"stdin=serial,usbkbd\0"
 #else
 #define CONSOLE_STDIN_SETTINGS \