[POWERPC] Split out asm-ppc/mmu.h portions for PowerPC 8xx

arch/powerpc still relies on asm-ppc/mmu.h for some 32-bit MMU types.
This patch is another step towards fixing this.  It takes the portions
of asm-ppc/mmu.h related to 8xx embedded CPUs which are still relevant
in arch/powerpc and puts them in a new asm-powerpc/mmu-8xx.h,
included when appropriate from asm-powerpc/mmu.h.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/include/asm-powerpc/mmu.h b/include/asm-powerpc/mmu.h
index 9b71403..d44d211 100644
--- a/include/asm-powerpc/mmu.h
+++ b/include/asm-powerpc/mmu.h
@@ -14,10 +14,9 @@
 #elif defined(CONFIG_FSL_BOOKE)
 /* Freescale Book-E software loaded TLB */
 #  include <asm/mmu-fsl-booke.h>
-#else
-/* Other 32-bit.  FIXME: split up the other 32-bit MMU types, and
- * revise for arch/powerpc */
-#  include <asm-ppc/mmu.h>
+#elif defined (CONFIG_PPC_8xx)
+/* Motorola/Freescale 8xx software loaded TLB */
+#  include <asm/mmu-8xx.h>
 #endif
 
 #endif /* __KERNEL__ */