Cleanup arch/i386/kernel/setup.c a little bit by:

* un-inlining machine_specific_memory_setup() (it's implementations are
  pretty big to be inlined anyway)

* remove setup_memory_region() by moving the code inside setup_arch()

I would also recommend BK-renaming all four files
(include/asm-i386/*/setup_arch_post.h) to ".c" and moving them into
arch/i386/*/, but that obviously is not needed in anyway.  But IMHO they
are clearly ".c" files, not ".h" files.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>