powerpc/85xx: Change deprecated binding for 85xx-based boards

The "fsl,85..." style compatible binding was to be deprecated
some time ago.  This patch corrects existing occurrences of
the incorrect binding.  The memory-controller and
l2-cache-controller are the only affected nodes.

Signed-off-by: Bradley Hughes <bhughes@silicontkx.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>