Rid of kernel error message:
[ 0.780828] orion-mdio d0072004.mdio: IRQ index 0 not found
on Marvell targets backporting the kernel commit fa2632f74e57
Signed-off-by: Daniel González Cabanelas <dgcbueu@gmail.com>
(cherry picked from commit d6831752367722e916bd15e5d1af79993c637a67)