powerpc/85xx: Add MPC8569MDS board support

The MPC8569 is similiar to the MPC8568.  It doubles the number of
QUICC Engine RISC cores from 2 to 4.  Removes eTSECs, TLU and adds
the eSDHC controller.

Signed-off-by: Haiying Wang <Haiying.Wang@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>