[POWERPC] Split out asm-ppc/mmu.h portions for the "classic" hash-based MMU

arch/powerpc still relies on asm-ppc/mmu.h for most 32-bit MMU types.
This is another step towards fixing this.  It takes the portions
of asm-ppc/mmu.h related to the "classic" 32-bit hash page table MMU
which are still relevant in arch/powerpc and puts them in a new
asm-powerpc/mmu-hash32.h, included when appropriate from
asm-powerpc/mmu.h.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/mmu.h b/include/asm-powerpc/mmu.h
index fe510ff..dae6a71f 100644
--- a/include/asm-powerpc/mmu.h
+++ b/include/asm-powerpc/mmu.h
@@ -5,6 +5,9 @@
 #ifdef CONFIG_PPC64
 /* 64-bit classic hash table MMU */
 #  include <asm/mmu-hash64.h>
+#elif defined(CONFIG_PPC_STD_MMU)
+/* 32-bit classic hash table MMU */
+#  include <asm/mmu-hash32.h>
 #elif defined(CONFIG_44x)
 /* 44x-style software loaded TLB */
 #  include <asm/mmu-44x.h>