Convert CONFIG_SYS_I2C_MXC et al to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_I2C_MXC
   CONFIG_SYS_I2C_MXC_I2C1
   CONFIG_SYS_I2C_MXC_I2C2
   CONFIG_SYS_I2C_MXC_I2C3
   CONFIG_SYS_I2C_MXC_I2C4

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/gwventana_nand_defconfig b/configs/gwventana_nand_defconfig
index a9c4e30..f988170 100644
--- a/configs/gwventana_nand_defconfig
+++ b/configs/gwventana_nand_defconfig
@@ -9,6 +9,9 @@
 CONFIG_ENV_OFFSET=0x1000000
 CONFIG_MX6QDL=y
 CONFIG_TARGET_GW_VENTANA=y
+CONFIG_SYS_I2C_MXC_I2C1=y
+CONFIG_SYS_I2C_MXC_I2C2=y
+CONFIG_SYS_I2C_MXC_I2C3=y
 CONFIG_CMD_EECONFIG=y
 CONFIG_CMD_GSC=y
 CONFIG_DEFAULT_DEVICE_TREE="imx6q-gw54xx"
@@ -84,6 +87,7 @@
 CONFIG_DWC_AHSATA=y
 CONFIG_SYS_I2C_LEGACY=y
 CONFIG_SPL_SYS_I2C_LEGACY=y
+CONFIG_SYS_I2C_MXC=y
 CONFIG_LED=y
 CONFIG_LED_BLINK=y
 CONFIG_LED_GPIO=y