armv8: Disable exception vectors in SPL by default

Commit 1416e2d2

 ("armv8: make SPL exception vectors optional") had a
typo in it which effectively disabled exception handling in SPL code always.

Since nobody complained, I guess we may as well disable exception handling
in SPL always by default.

So fix the bug to make the config option effective, but disable exception
handling in SPL by default. This gets us to the same functionality as before
by default, but with much less code included in the binary.
Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Matthias Brugger <mbrugger@suse.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>

arch/arm/cpu/armv8/Kconfig

@@ -3,7 +3,7 @@ if ARM64
 config ARMV8_SPL_EXCEPTION_VECTORS
 	bool "Install crash dump exception vectors"
 	depends on SPL
-	default y
+	default n
 	help
 	  The default exception vector table is only used for the crash
 	  dump, but still takes quite a lot of space in the image size.

arch/arm/cpu/armv8/start.S

@@ -88,7 +88,7 @@ pie_fixup_done:
 	bl reset_sctrl
 #endif
 
-#if defined(CONFIG_ARMV8__SPL_EXCEPTION_VECTORS) || !defined(CONFIG_SPL_BUILD)
+#if defined(CONFIG_ARMV8_SPL_EXCEPTION_VECTORS) || !defined(CONFIG_SPL_BUILD)
 .macro	set_vbar, regname, reg
 	msr	\regname, \reg
 .endm
@@ -354,7 +354,7 @@ ENDPROC(smp_kick_all_cpus)
 /*-----------------------------------------------------------------------*/
 
 ENTRY(c_runtime_cpu_setup)
-#if defined(CONFIG_ARMV8__SPL_EXCEPTION_VECTORS) || !defined(CONFIG_SPL_BUILD)
+#if defined(CONFIG_ARMV8_SPL_EXCEPTION_VECTORS) || !defined(CONFIG_SPL_BUILD)
 	/* Relocate vBAR */
 	adr	x0, vectors
 	switch_el x1, 3f, 2f, 1f