ARM: re-enable MVGBE for edminiv2

This was unintentionally disabled when moving MVGBE to Kconfig.

Fixes: commit ed52ea50 ("net: add Kconfig for MVGBE")
Signed-off-by: Chris Packham <judge.packham@gmail.com>

configs/edminiv2_defconfig

@@ -26,6 +26,8 @@ CONFIG_ENV_IS_IN_FLASH=y
 CONFIG_MVSATA_IDE=y
 # CONFIG_MMC is not set
 CONFIG_MTD_NOR_FLASH=y
+CONFIG_NETDEVICES=y
+CONFIG_MVGBE=y
 CONFIG_SYS_NS16550=y
 CONFIG_USB=y
 CONFIG_USB_EHCI_HCD=y