soc: st: stm32 retrieves the base address of the external memory

Get the CONFIG_FLASH_BASE_ADDRESS when the flash is external xSPI
device. Its address is given by the second <reg> of the
compatible = "st,stm32-xspi";

Signed-off-by: Francois Ramu <francois.ramu@st.com>

Author: FRASTM

soc/st/stm32/Kconfig.defconfig

@@ -23,6 +23,13 @@ DT_STM32_RCC_CLOCK_FREQ := $(dt_node_int_prop_int,$(DT_STM32_RCC_PATH),clock-fre
 DT_ST_PRESCALER := st,prescaler
 DT_STM32_LPTIM_PATH := $(dt_nodelabel_path,stm32_lp_tick_source)
 
+DT_CHOSEN_Z_FLASH := zephyr,flash
+DT_COMPAT_XSPI := st,stm32-xspi
+
+DT_CHOSEN_FLASH_NODE := $(dt_chosen_path,$(DT_CHOSEN_Z_FLASH))
+DT_CHOSEN_FLASH_PARENT := $(dt_node_parent,$(DT_CHOSEN_FLASH_NODE))
+DT_FLASH_PARENT_IS_XSPI := $(dt_node_has_compat,$(DT_CHOSEN_FLASH_PARENT),$(DT_COMPAT_XSPI))
+
 config SYS_CLOCK_HW_CYCLES_PER_SEC
 	default "$(DT_STM32_RCC_CLOCK_FREQ)" if "$(dt_nodelabel_enabled,rcc)"
 
@@ -70,4 +77,9 @@ config USE_DT_CODE_PARTITION
 config BUILD_WITH_TFM
 	default y if TRUSTED_EXECUTION_NONSECURE
 
+config FLASH_BASE_ADDRESS
+	default $(dt_node_reg_addr_hex,$(DT_CHOSEN_FLASH_PARENT),1) \
+		if $(DT_FLASH_PARENT_IS_XSPI)
+	default $(dt_chosen_reg_addr_hex,$(DT_CHOSEN_Z_FLASH))
+
 endif # SOC_FAMILY_STM32