Add the missing input mux for ENET2 mdio. Without this setting, it is not
possible to read the MDIO answers back from the PHY.
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>