fs_enet: fix freescale FCC ethernet dp buffer alignment

The RIPTR and TIPTR  (receive/transmit internal temporary data pointer),
used by microcode as a temporary buffer for data, must be 32-byte aligned
according to the RM for MPC8247.

Tested on mgcoge.

Signed-off-by: Clive Stubbings <clive.stubbings@xentech.co.uk>
Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
cc: Pantelis Antoniou <pantelis.antoniou@gmail.com>
cc: Vitaly Bordug <vbordug@ru.mvista.com>
cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@conan.davemloft.net>