powerpc/mm: Move hpte_insert_repeating() prototype

It fixes this W=1 compile error :

../arch/powerpc/mm/book3s64/hash_utils.c:1867:6: error: no previous prototype for ‘hpte_insert_repeating’ [-Werror=missing-prototypes]
 1867 | long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
      |      ^~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210104143206.695198-14-clg@kaod.org

arch/powerpc/include/asm/book3s/64/mmu-hash.h

@@ -454,6 +454,8 @@ static inline unsigned long hpt_hash(unsigned long vpn,
 #define HPTE_NOHPTE_UPDATE	0x2
 #define HPTE_USE_KERNEL_KEY	0x4
 
+long hpte_insert_repeating(unsigned long hash, unsigned long vpn, unsigned long pa,
+			   unsigned long rlags, unsigned long vflags, int psize, int ssize);
 extern int __hash_page_4K(unsigned long ea, unsigned long access,
 			  unsigned long vsid, pte_t *ptep, unsigned long trap,
 			  unsigned long flags, int ssize, int subpage_prot);

arch/powerpc/mm/book3s64/hash_hugetlbpage.c

@@ -16,10 +16,6 @@
 unsigned int hpage_shift;
 EXPORT_SYMBOL(hpage_shift);
 
-extern long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
-				  unsigned long pa, unsigned long rlags,
-				  unsigned long vflags, int psize, int ssize);
-
 int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
 		     pte_t *ptep, unsigned long trap, unsigned long flags,
 		     int ssize, unsigned int shift, unsigned int mmu_psize)