rename symbol: CONFIG_STM32 -> CONFIG_ARCH_STM32

Have this symbol follow the pattern of all other such symbols.

Signed-off-by: Trevor Woerner <twoerner@gmail.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 6152b11..ef7da27 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1607,7 +1607,7 @@
 	  Support for UniPhier SoC family developed by Socionext Inc.
 	  (formerly, System LSI Business Division of Panasonic Corporation)
 
-config STM32
+config ARCH_STM32
 	bool "Support STMicroelectronics STM32 MCU with cortex M"
 	select CPU_V7M
 	select DM
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index e91b37f..94eb50b 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -73,7 +73,7 @@
 machine-$(CONFIG_ARCH_S5PC1XX)		+= s5pc1xx
 machine-$(CONFIG_ARCH_SNAPDRAGON)	+= snapdragon
 machine-$(CONFIG_ARCH_SOCFPGA)		+= socfpga
-machine-$(CONFIG_STM32)			+= stm32
+machine-$(CONFIG_ARCH_STM32)		+= stm32
 machine-$(CONFIG_ARCH_STM32MP)		+= stm32mp
 machine-$(CONFIG_ARCH_SUNXI)		+= sunxi
 machine-$(CONFIG_ARCH_TEGRA)		+= tegra
diff --git a/arch/arm/mach-stm32/Kconfig b/arch/arm/mach-stm32/Kconfig
index cea5ee2..b42b056 100644
--- a/arch/arm/mach-stm32/Kconfig
+++ b/arch/arm/mach-stm32/Kconfig
@@ -1,4 +1,4 @@
-if STM32
+if ARCH_STM32
 
 config STM32F4
 	bool "stm32f4 family"