Driver/ddr: Add support of different DDR base address

Driver/ddr: Add support of different DDR base address

DDR base address has been the same from the view of core and DDR
controllers. This has changed for Freescale ARM-based SoCs. Controllers
setup DDR memory in a contiguous space and cores view it at separated
locations.

Signed-off-by: York Sun <yorksun@freescale.com>