MIPS: SGI-IP27: Use the _AC() macro in spaces.h

The attached patch wraps several of the macros in IP27's spaces.h
header file with the _AC() macro.  This matches most of the other
spaces.h files in the MIPS tree.

Signed-off-by: Joshua Kinard <kumba@gentoo.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>