stm32mp: handle SYSRESET

Add support of sysreset with generic driver "syscon-reboot"
provided by RCC, for U-boot and for SPL.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/arch/arm/mach-stm32mp/Kconfig b/arch/arm/mach-stm32mp/Kconfig
index 9771af9..8ca97bf 100644
--- a/arch/arm/mach-stm32mp/Kconfig
+++ b/arch/arm/mach-stm32mp/Kconfig
@@ -16,6 +16,7 @@
 	select SPL_RESET_SUPPORT
 	select SPL_SERIAL_SUPPORT
 	select SPL_SYSCON
+	select SPL_DRIVERS_MISC_SUPPORT
 	imply SPL_LIBDISK_SUPPORT
 
 config SYS_SOC
@@ -26,6 +27,7 @@
 	select CPU_V7
 	select PINCTRL_STM32
 	select STM32_RESET
+	select SYSRESET_SYSCON
 	help
 		target STMicroelectronics SOC STM32MP1 family
 		STMicroelectronics MPU with core ARMv7