stm32: Add support for additional i2c bus (#647)

Signed-off-by: Russell Cloran <rcloran@gmail.com>
Co-authored-by: Russell Cloran <rcloran@gmail.com>

Author: thetic

src/stm32/i2c.c

@@ -32,6 +32,8 @@ DECL_ENUMERATION("i2c_bus", "i2c2a", 4);
 DECL_CONSTANT_STR("BUS_PINS_i2c2a", "PH4,PH5");
 DECL_ENUMERATION("i2c_bus", "i2c3a", 5);
 DECL_CONSTANT_STR("BUS_PINS_i2c3a", "PH7,PH8");
+DECL_ENUMERATION("i2c_bus", "i2c2_PF1_PF0", 6);
+DECL_CONSTANT_STR("BUS_PINS_i2c2_PF1_PF0", "PF1,PF0");
   #endif
 #endif
 
@@ -44,6 +46,7 @@ static const struct i2c_info i2c_bus[] = {
   #if CONFIG_MACH_STM32F2 || CONFIG_MACH_STM32F4x5
     { I2C2, GPIO('H', 4), GPIO('H', 5) },
     { I2C3, GPIO('H', 7), GPIO('H', 8) },
+    { I2C2, GPIO('F', 1), GPIO('F', 0) },
   #endif
 #endif
 };