arm: mvebu: a3720: Create Kconfig option for I2C_MV

Move the config option CONFIG_I2C_MV to a Kconfig option
CONFIG_SYS_I2C_MV and move the default definition from config header
files into defconfigs.

Signed-off-by: Marek BehĂșn <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index 66bd6fe..7c447a8 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -627,6 +627,12 @@
 	  Add support for the Arm Ltd Versatile Express I2C driver. The I2C host
 	  controller is present in the development boards manufactured by Arm Ltd.
 
+config SYS_I2C_MV
+	bool "Marvell PXA (Armada 3720) I2C driver"
+	help
+	  Support for PXA based I2C controller used on Armada 3720 SoC.
+	  In Linux, this driver is called i2c-pxa.
+
 config SYS_I2C_MVTWSI
 	bool "Marvell I2C driver"
 	help