powerpc/vphn: move VPHN parsing logic to a separate file

The goal behind this patch is to be able to write userland tests for the
VPHN parsing code.

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index 438dcd3..9c8770b 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -24,6 +24,7 @@
 obj-$(CONFIG_44x)		+= 44x_mmu.o
 obj-$(CONFIG_PPC_FSL_BOOK3E)	+= fsl_booke_mmu.o
 obj-$(CONFIG_NEED_MULTIPLE_NODES) += numa.o
+obj-$(CONFIG_PPC_SPLPAR)	+= vphn.o
 obj-$(CONFIG_PPC_MM_SLICES)	+= slice.o
 obj-y				+= hugetlbpage.o
 ifeq ($(CONFIG_HUGETLB_PAGE),y)