watchdog: don't autostart watchdog on STM32MP architecture

On STM32MP reference boards, the watchdog is started by a previous
boot stage (e.g. bootrom or secure OS), so the config flag
WATCHDOG_AUTOSTART is not required.
It's preferable to rely on the DT properties "u-boot,autostart" or
"u-boot,noautostart", if needed.

For backward compatibility on defconfigs that are based on SPL,
thus cannot rely on a previous boot stage for starting the
watchdog, enable WATCHDOG_AUTOSTART in their respective defconfig.
The change in stm32mp15_dhsom.config is propagated to:
- configs/stm32mp15_dhcom_basic.config
- configs/stm32mp15_dhcor_basic.config
and then to:
- stm32mp15_dhcom_basic_defconfig
- stm32mp15_dhcom_drc02_basic_defconfig
- stm32mp15_dhcom_pdk2_basic_defconfig
- stm32mp15_dhcom_picoitx_basic_defconfig
- stm32mp15_dhcor_avenger96_basic_defconfig
- stm32mp15_dhcor_basic_defconfig
- stm32mp15_dhcor_drc_compact_basic_defconfig
- stm32mp15_dhcor_testbench_basic_defconfig

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>

configs/stm32mp15-icore-stm32mp1-ctouch2_defconfig

@@ -89,6 +89,7 @@ CONFIG_DM_RTC=y
 CONFIG_RTC_STM32=y
 CONFIG_SERIAL_RX_BUFFER=y
 CONFIG_SYSRESET_SYSCON=y
+CONFIG_WATCHDOG_AUTOSTART=y
 CONFIG_WDT=y
 CONFIG_WDT_STM32MP=y
 # CONFIG_BINMAN_FDT is not set

configs/stm32mp15-icore-stm32mp1-edimm2.2_defconfig

@@ -89,6 +89,7 @@ CONFIG_DM_RTC=y
 CONFIG_RTC_STM32=y
 CONFIG_SERIAL_RX_BUFFER=y
 CONFIG_SYSRESET_SYSCON=y
+CONFIG_WATCHDOG_AUTOSTART=y
 CONFIG_WDT=y
 CONFIG_WDT_STM32MP=y
 # CONFIG_BINMAN_FDT is not set

configs/stm32mp15-microgea-stm32mp1-microdev2-of7_defconfig

@@ -89,6 +89,7 @@ CONFIG_DM_RTC=y
 CONFIG_RTC_STM32=y
 CONFIG_SERIAL_RX_BUFFER=y
 CONFIG_SYSRESET_SYSCON=y
+CONFIG_WATCHDOG_AUTOSTART=y
 CONFIG_WDT=y
 CONFIG_WDT_STM32MP=y
 # CONFIG_BINMAN_FDT is not set

configs/stm32mp15-microgea-stm32mp1-microdev2_defconfig

@@ -89,6 +89,7 @@ CONFIG_DM_RTC=y
 CONFIG_RTC_STM32=y
 CONFIG_SERIAL_RX_BUFFER=y
 CONFIG_SYSRESET_SYSCON=y
+CONFIG_WATCHDOG_AUTOSTART=y
 CONFIG_WDT=y
 CONFIG_WDT_STM32MP=y
 # CONFIG_BINMAN_FDT is not set

configs/stm32mp15_basic_defconfig

@@ -191,6 +191,7 @@ CONFIG_SPLASH_SCREEN_ALIGN=y
 CONFIG_BMP_16BPP=y
 CONFIG_BMP_24BPP=y
 CONFIG_BMP_32BPP=y
+CONFIG_WATCHDOG_AUTOSTART=y
 CONFIG_WDT=y
 CONFIG_WDT_STM32MP=y
 # CONFIG_BINMAN_FDT is not set

configs/stm32mp15_dhsom.config

@@ -76,3 +76,4 @@ CONFIG_PREBOOT="run dh_preboot"
 CONFIG_SYS_SPI_U_BOOT_OFFS=0x80000
 CONFIG_TARGET_DH_STM32MP1_PDK2=y
 CONFIG_USE_SERVERIP=y
+CONFIG_WATCHDOG_AUTOSTART=y

drivers/watchdog/Kconfig

@@ -15,6 +15,7 @@ config WATCHDOG_AUTOSTART
 	bool "Automatically start watchdog timer"
 	depends on WDT
 	default n if ARCH_SUNXI
+	default n if ARCH_STM32MP
 	default y
 	help
 	  Automatically start watchdog timer and start servicing it during