The setup code of the OpenMesh OM5P ACv2 device uses nothing
from the mdio-gpio.h header, so remove the inclusion of that.
Also remove the kernel version check which is needed only
because the mdio-gpio.h header exists in a different path
in older kernels.
Compile tested only.
Cc: Sven Eckelmann <sven.eckelmann@openmesh.com>
Signed-off-by: Gabor Juhos <juhosg@freemail.hu>