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/pogo_e02_defconfig b/configs/pogo_e02_defconfig
index 8d77200..13b40d5 100644
--- a/configs/pogo_e02_defconfig
+++ b/configs/pogo_e02_defconfig
@@ -23,8 +23,8 @@
 CONFIG_OF_CONTROL=y
 CONFIG_ENV_IS_IN_NAND=y
 # CONFIG_MMC is not set
-CONFIG_NETDEVICES=y
 CONFIG_MVGBE=y
+CONFIG_MII=y
 CONFIG_SYS_NS16550=y
 CONFIG_USB=y
 CONFIG_USB_EHCI_HCD=y