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/flea3_defconfig b/configs/flea3_defconfig
index e91017d..61d77eb 100644
--- a/configs/flea3_defconfig
+++ b/configs/flea3_defconfig
@@ -5,6 +5,9 @@
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_ENV_SIZE=0x10000
 CONFIG_ENV_SECT_SIZE=0x10000
+CONFIG_SYS_I2C_MXC_I2C1=y
+CONFIG_SYS_I2C_MXC_I2C2=y
+CONFIG_SYS_I2C_MXC_I2C3=y
 CONFIG_FIT=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_BOOTDELAY=3
@@ -30,6 +33,8 @@
 CONFIG_ENV_ADDR_REDUND=0xA0090000
 CONFIG_MXC_GPIO=y
 CONFIG_SYS_I2C_LEGACY=y
+CONFIG_SYS_I2C_MXC=y
+CONFIG_SYS_MXC_I2C3_SLAVE=0xfe
 # CONFIG_MMC is not set
 CONFIG_MTD=y
 CONFIG_MTD_NOR_FLASH=y