new devmap.[ch] files. Emphasize the MD nature of these things by using
the prefix arm_devmap_ on the function and type names (already a few of
these things found their way into MI code, hopefully it will be harder to
do by accident in the future).
The only remaining user was the code that allocates bounce pages for armv4
busdma. It's not clear why bounce pages would need uncached memory, but
if that ever changes, kmem_alloc_attr() would be the way to get it.
really need it. That would be almost everywhere it was included. Add
it in a couple files that really do need it and were previously getting
it by accident via another header.
included by vm/pmap.h, which is a prerequisite for arm/machine/pmap.h
so there's no reason to ever include it directly.
Thanks to alc@ for pointing this out.
