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/warp_defconfig b/configs/warp_defconfig
index 6e81acc..0dc800e 100644
--- a/configs/warp_defconfig
+++ b/configs/warp_defconfig
@@ -6,6 +6,8 @@
 CONFIG_ENV_OFFSET=0x60000
 CONFIG_MX6SL=y
 CONFIG_TARGET_WARP=y
+CONFIG_SYS_I2C_MXC_I2C1=y
+CONFIG_SYS_I2C_MXC_I2C2=y
 # CONFIG_CMD_BMODE is not set
 CONFIG_SUPPORT_RAW_INITRD=y
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=board/warp/imximage.cfg"
@@ -33,6 +35,7 @@
 CONFIG_DFU_MMC=y
 CONFIG_SYS_DFU_DATA_BUF_SIZE=0x1000000
 CONFIG_SYS_I2C_LEGACY=y
+CONFIG_SYS_I2C_MXC=y
 CONFIG_SUPPORT_EMMC_BOOT=y
 CONFIG_FSL_USDHC=y
 CONFIG_MXC_UART=y