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/Colombus_defconfig b/configs/Colombus_defconfig
index 0542520..ac97501 100644
--- a/configs/Colombus_defconfig
+++ b/configs/Colombus_defconfig
@@ -20,6 +20,7 @@
 CONFIG_SYS_I2C_SOFT=y
 CONFIG_SYS_I2C_SOFT_SPEED=50000
 CONFIG_SYS_I2C_SOFT_SLAVE=0x00
+CONFIG_SYS_I2C_MVTWSI=y
 CONFIG_PHY_REALTEK=y
 CONFIG_ETH_DESIGNWARE=y
 CONFIG_RGMII=y