85xx: Fix how we map DDR memory

Previously we only allowed power-of-two memory sizes and didnt
handle >2G of memory.  Now we will map up to CONFIG_MAX_MEM_MAPPED
and should properly handle any size that we can make in the TLBs
we have available to us

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
4 files changed