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/sc_sps_1_defconfig b/configs/sc_sps_1_defconfig
index 04acfdc..12387d4 100644
--- a/configs/sc_sps_1_defconfig
+++ b/configs/sc_sps_1_defconfig
@@ -30,6 +30,7 @@
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_MMC_MXS=y
 CONFIG_PHYLIB=y
+CONFIG_MII=y
 CONFIG_CONS_INDEX=0
 CONFIG_USB=y
 CONFIG_USB_EHCI_HCD=y