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/apf27_defconfig b/configs/apf27_defconfig
index 55225fb..f2a4e95 100644
--- a/configs/apf27_defconfig
+++ b/configs/apf27_defconfig
@@ -42,4 +42,5 @@
 CONFIG_NAND=y
 CONFIG_NAND_MXC=y
 CONFIG_SYS_NAND_BUSWIDTH_16BIT=y
+CONFIG_MII=y
 CONFIG_OF_LIBFDT=y