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/orangepi_pc_plus_defconfig b/configs/orangepi_pc_plus_defconfig
index 3aeb2de..d6a04ea 100644
--- a/configs/orangepi_pc_plus_defconfig
+++ b/configs/orangepi_pc_plus_defconfig
@@ -7,6 +7,7 @@
 CONFIG_MMC_SUNXI_SLOT_EXTRA=2
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
 CONFIG_SPL_I2C=y
+CONFIG_SYS_I2C_MVTWSI=y
 CONFIG_SUN8I_EMAC=y
 CONFIG_SY8106A_POWER=y
 CONFIG_USB_EHCI_HCD=y