Remove CONFIG_MVGBE from config_whitelist.txt

Now that there are more boards defining this it can be removed from the
whitelist.

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

scripts/config_whitelist.txt

@@ -1333,7 +1333,6 @@ CONFIG_MTD_UBI_MODULE
 CONFIG_MULTI_CS
 CONFIG_MUSB_HOST
 CONFIG_MVEBU_MMC
-CONFIG_MVGBE
 CONFIG_MVGBE_PORTS
 CONFIG_MVMFP_V2
 CONFIG_MVS