sparc64: add the missing pgd_page definition

sparc64 only had pgd_page_vaddr, but not pgd_page.

[[email protected]: fix sparc64 build]
  Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Christoph Hellwig <[email protected]>
Cc: David Miller <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: James Hogan <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Khalid Aziz <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Paul Burton <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

arch/sparc/include/asm/pgtable_64.h

@@ -864,6 +864,9 @@ static inline unsigned long pud_page_vaddr(pud_t pud)
 #define pgd_present(pgd)		(pgd_val(pgd) != 0U)
 #define pgd_clear(pgdp)			(pgd_val(*(pgdp)) = 0UL)
 
+/* only used by the stubbed out hugetlb gup code, should never be called */
+#define pgd_page(pgd)			NULL
+
 static inline unsigned long pud_large(pud_t pud)
 {
 	pte_t pte = __pte(pud_val(pud));