stm32: Initial support for stm32f070

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/stm32/Kconfig

@@ -6,8 +6,8 @@ config STM32_SELECT
     bool
     default y
     select HAVE_GPIO
-    select HAVE_GPIO_ADC
-    select HAVE_GPIO_I2C
+    select HAVE_GPIO_ADC if !MACH_STM32F0
+    select HAVE_GPIO_I2C if !MACH_STM32F0
     select HAVE_GPIO_SPI
     select HAVE_GPIO_BITBANGING
 
@@ -29,15 +29,20 @@ choice
     config MACH_STM32F446
         bool "STM32F446"
         select MACH_STM32F4
+    config MACH_STM32F070
+        bool "STM32F070"
+        select MACH_STM32F0
 endchoice
 
+config MACH_STM32F0
+    bool
 config MACH_STM32F1
     bool
 config MACH_STM32F4
     bool
 config HAVE_STM32_USBFS
     bool
-    default y if MACH_STM32F103
+    default y if MACH_STM32F103 || MACH_STM32F0
     default n
 config HAVE_STM32_USBOTG
     bool
@@ -46,6 +51,7 @@ config HAVE_STM32_USBOTG
 
 config MCU
     string
+    default "stm32f070xb" if MACH_STM32F070
     default "stm32f103xe" if MACH_STM32F103
     default "stm32f405xx" if MACH_STM32F405
     default "stm32f407xx" if MACH_STM32F407
@@ -53,12 +59,14 @@ config MCU
 
 config CLOCK_FREQ
     int
+    default 48000000 if MACH_STM32F0
     default 72000000 if MACH_STM32F103
     default 168000000 if MACH_STM32F405 || MACH_STM32F407
     default 180000000 if MACH_STM32F446
 
 config FLASH_SIZE
     hex
+    default 0x20000 if MACH_STM32F070
     default 0x10000 if MACH_STM32F103
     default 0x80000 if MACH_STM32F4
 
@@ -68,6 +76,7 @@ config RAM_START
 
 config RAM_SIZE
     hex
+    default 0x4000 if MACH_STM32F070
     default 0x5000 if MACH_STM32F103
     default 0x20000 if MACH_STM32F4