AM437x EPOS evm use external clock for RMII interface.
Enable the same in DT.
Signed-off-by: NGeorge Cherian <george.cherian@ti.com>
Reported-by: NNishanth Menon <nm@ti.com>
Tested-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>