mpc85xx: Implement workaround for erratum DDR-A003

Erratum DDR-A003 requires workaround to correctly set RCW10 for registered DIMM.
Also adding polling after enabling DDR controller to ensure completion.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
4 files changed