Merge branch 'Fixes-for-OF_MDIO-flag'

Merge branch 'Fixes-for-OF_MDIO-flag'

Dan Murphy says:

====================
Fixes for OF_MDIO flag

There are some residual drivers that check the CONFIG_OF_MDIO flag using the
if defs. Using this check does not work when the OF_MDIO is configured as a
module. Using the IS_ENABLED macro checks if the flag is declared as built-in
or as a module.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>