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/ts4800_defconfig b/configs/ts4800_defconfig
index 9d7a516..e1766bd 100644
--- a/configs/ts4800_defconfig
+++ b/configs/ts4800_defconfig
@@ -17,6 +17,7 @@
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_FSL_ESDHC=y
 CONFIG_PHYLIB=y
+CONFIG_MII=y
 CONFIG_SPI=y
 CONFIG_MXC_SPI=y
 CONFIG_OF_LIBFDT=y