[MIPS] Allow generic spaces.h to be included by platform specific ones

Before this patch, when a platform needed to customize one constant in
spaces.h, they need to redefine all of them.

Now they can just redefine one constant and include the generic file
header at the end:

	#include <asm/mach-generic/spaces.h>

This patch doesn't allow to redefine CAC_BASE, IO_BASE and UNCAC_BASE
for 32 bits platforms because there's no need to do so.

This will avoid some macro duplications. It's important specially if
we'll add complex macros.

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

 delete mode 100644 include/asm-mips/mach-ip32/spaces.h