soc: stm32f407xg: rename SOC config flag

Rename SOC_STM32F407XX to SOC_STM32F407XG to keep flash
size information.
Aim is to be able to distinguish flash size variants of
the SoC when needed (for instance in dts/arm/st/mem.h file).

Change-Id: I0afa16e86b7c99b9e685004f96beeb888f9e7568
Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>
diff --git a/arch/arm/soc/st_stm32/stm32f4/Kconfig.defconfig.stm32f407xx b/arch/arm/soc/st_stm32/stm32f4/Kconfig.defconfig.stm32f407xx
index 2af3837..719306e 100644
--- a/arch/arm/soc/st_stm32/stm32f4/Kconfig.defconfig.stm32f407xx
+++ b/arch/arm/soc/st_stm32/stm32f4/Kconfig.defconfig.stm32f407xx
@@ -5,7 +5,7 @@
 # SPDX-License-Identifier: Apache-2.0
 #
 
-if SOC_STM32F407XX
+if SOC_STM32F407XG
 
 config SOC
 	string
@@ -15,4 +15,4 @@
 	int
 	default 82
 
-endif # SOC_STM32F407XX
+endif # SOC_STM32F407XG
diff --git a/arch/arm/soc/st_stm32/stm32f4/Kconfig.soc b/arch/arm/soc/st_stm32/stm32f4/Kconfig.soc
index 4cce8ff..470a5ac 100644
--- a/arch/arm/soc/st_stm32/stm32f4/Kconfig.soc
+++ b/arch/arm/soc/st_stm32/stm32f4/Kconfig.soc
@@ -12,7 +12,7 @@
 config SOC_STM32F401XE
 	bool "STM32F401XE"
 
-config SOC_STM32F407XX
+config SOC_STM32F407XG
 	bool "STM32F407XX"
 
 config SOC_STM32F411XE
diff --git a/dts/arm/st/mem.h b/dts/arm/st/mem.h
index a3616a6..a269e2d 100644
--- a/dts/arm/st/mem.h
+++ b/dts/arm/st/mem.h
@@ -24,7 +24,7 @@
 #elif defined(CONFIG_SOC_STM32F401XE)
 #define DT_FLASH_SIZE		__SIZE_K(512)
 #define DT_SRAM_SIZE		__SIZE_K(96)
-#elif defined(CONFIG_SOC_STM32F407XX)
+#elif defined(CONFIG_SOC_STM32F407XG)
 #define DT_FLASH_SIZE		__SIZE_K(1024)
 #define DT_SRAM_SIZE		__SIZE_K(192)
 #elif defined(CONFIG_SOC_STM32F411XE)