arm: stm32mp: add support of STM32MP13x

Introduce the code in mach-stm32mp and the configuration file
stm32mp13_defconfig for the new STM32MP family.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
diff --git a/configs/stm32mp15_basic_defconfig b/configs/stm32mp15_basic_defconfig
index a08bcde..8ae668c 100644
--- a/configs/stm32mp15_basic_defconfig
+++ b/configs/stm32mp15_basic_defconfig
@@ -9,8 +9,8 @@
 CONFIG_SPL_MMC=y
 CONFIG_SPL=y
 CONFIG_CMD_STM32KEY=y
-CONFIG_TARGET_ST_STM32MP15x=y
 CONFIG_TYPEC_STUSB160X=y
+CONFIG_TARGET_ST_STM32MP15x=y
 CONFIG_ENV_OFFSET_REDUND=0x2C0000
 CONFIG_CMD_STM32PROG=y
 CONFIG_SPL_SPI_FLASH_SUPPORT=y