ARM: dts: stm32: Fix GPIO hog flags on DHCOM PicoITX

The GPIO hog flags are ignored by gpiolib-of.c now, set the flags to 0.
Due to a change in gpiolib-of.c, setting flags to GPIO_ACTIVE_LOW and
using output-low DT property leads to the GPIO being set high instead.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>

arch/arm/dts/stm32mp15xx-dhcom-picoitx.dts

@@ -37,7 +37,7 @@
 	 */
 	usb-port-power {
 		gpio-hog;
-		gpios = <13 GPIO_ACTIVE_LOW>;
+		gpios = <13 0>;
 		output-low;
 		line-name = "usb-port-power";
 	};