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/ba10_tv_box_defconfig b/configs/ba10_tv_box_defconfig
index 8311556..747d205 100644
--- a/configs/ba10_tv_box_defconfig
+++ b/configs/ba10_tv_box_defconfig
@@ -10,6 +10,7 @@
 CONFIG_VIDEO_COMPOSITE=y
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
 CONFIG_SPL_I2C=y
+CONFIG_SYS_I2C_MVTWSI=y
 CONFIG_MII=y
 CONFIG_SUN4I_EMAC=y
 CONFIG_USB_EHCI_HCD=y