linux-wandboard

sh: enable LMB region setup via machvec.

This plugs in a memory init callback in the machvec to permit boards to
wire up various bits of memory directly in to LMB. A generic machvec
implementation is provided that simply wraps around the normal
Kconfig-derived memory start/size.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>