Convert CONFIG_MII et al to Kconfig

This converts the following to Kconfig:
   CONFIG_MII
   CONFIG_DRIVER_TI_EMAC

Signed-off-by: Adam Ford <aford173@gmail.com>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/configs/am335x_igep003x_defconfig b/configs/am335x_igep003x_defconfig
index aaa5397..d782976 100644
--- a/configs/am335x_igep003x_defconfig
+++ b/configs/am335x_igep003x_defconfig
@@ -44,6 +44,7 @@
 CONFIG_NAND=y
 CONFIG_MTD_UBI_FASTMAP=y
 CONFIG_DRIVER_TI_CPSW=y
+CONFIG_MII=y
 CONFIG_SYS_NS16550=y
 CONFIG_SPI=y
 CONFIG_OMAP3_SPI=y