fs_enet: Remove unused fields in the fs_mii_bb_platform_info structure.

The mdio_port, mdio_bit, mdc_port and mdc_bit fields in the
fs_mii_bb_platform_info structure are left-overs from the move to the Phy
Abstraction Layer subsystem. They are not used anymore and can be safely
removed.

Signed-off-by: Laurent Pinchart <laurentp@cse-semaphore.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>