Convert CONFIG_SYS_I2C_MVTWSI to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_I2C_MVTWSI

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/A13-OLinuXinoM_defconfig b/configs/A13-OLinuXinoM_defconfig
index 568f64e..499f444 100644
--- a/configs/A13-OLinuXinoM_defconfig
+++ b/configs/A13-OLinuXinoM_defconfig
@@ -13,6 +13,7 @@
 CONFIG_VIDEO_LCD_POWER="PB10"
 CONFIG_VIDEO_LCD_BL_PWM="PB2"
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
+CONFIG_SYS_I2C_MVTWSI=y
 CONFIG_SUNXI_NO_PMIC=y
 CONFIG_CONS_INDEX=2
 CONFIG_USB_EHCI_HCD=y