ARM: stm32: Introduce MACH_STM32F469 flag

This patch introduces the MACH_STM32F469 to make possible to only select
STM32F469 pinctrl driver

By default, all the MACH_STM32Fxxx flags will be set with STM32 defconfig.
Signed-off-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

arch/arm/mach-stm32/Kconfig

@@ -15,6 +15,11 @@ config MACH_STM32F429
 	depends on ARCH_STM32
 	default y
 
+config MACH_STM32F469
+	bool "STMicrolectronics STM32F469"
+	depends on ARCH_STM32
+	default y
+
 config MACH_STM32F746
 	bool "STMicrolectronics STM32F746"
 	depends on ARCH_STM32