powerpc/mm: make hugetlbpage.c depend on CONFIG_HUGETLB_PAGE

The only function in hugetlbpage.c which doesn't depend on
CONFIG_HUGETLB_PAGE is gup_hugepte(), and this function is
only called from gup_huge_pd() which depends on
CONFIG_HUGETLB_PAGE so all the content of hugetlbpage.c
depends on CONFIG_HUGETLB_PAGE.

This patch modifies Makefile to only compile hugetlbpage.c
when CONFIG_HUGETLB_PAGE is set.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/mm/Makefile

@@ -15,7 +15,7 @@ obj-$(CONFIG_PPC_BOOK3S_64)	+= pgtable-frag.o
 obj-$(CONFIG_PPC32)		+= pgtable-frag.o
 obj-$(CONFIG_NEED_MULTIPLE_NODES) += numa.o
 obj-$(CONFIG_PPC_MM_SLICES)	+= slice.o
-obj-y				+= hugetlbpage.o
+obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
 obj-$(CONFIG_NOT_COHERENT_CACHE) += dma-noncoherent.o
 obj-$(CONFIG_HIGHMEM)		+= highmem.o
 obj-$(CONFIG_PPC_COPRO_BASE)	+= copro_fault.o

arch/powerpc/mm/hugetlbpage.c

@@ -26,9 +26,6 @@
 #include <asm/hugetlb.h>
 #include <asm/pte-walk.h>
 
-
-#ifdef CONFIG_HUGETLB_PAGE
-
 #define PAGE_SHIFT_64K	16
 #define PAGE_SHIFT_512K	19
 #define PAGE_SHIFT_8M	23
@@ -754,8 +751,6 @@ void flush_dcache_icache_hugepage(struct page *page)
 	}
 }
 
-#endif /* CONFIG_HUGETLB_PAGE */
-
 int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
 		unsigned long end, int write, struct page **pages, int *nr)
 {