The DRAM base has been zero for Power SoCs. It could be non-zero
for ARM SoCs. Use a macro instead of hard-coding to zero.
Signed-off-by: York Sun <yorksun@freescale.com>
Freescale DDR driver has been used for mpc83xx, mpc85xx, mpc86xx SoCs.
The similar DDR controllers will be used for ARM-based SoCs.
Signed-off-by: York Sun <yorksun@freescale.com>