powerpc: Move htab_remove_mapping function prototype into header file

A recent patch added a function prototype for htab_remove_mapping in
c code. Fix it.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/mmu-hash64.h

@@ -342,6 +342,8 @@ extern void hash_failure_debug(unsigned long ea, unsigned long access,
 extern int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
 			     unsigned long pstart, unsigned long prot,
 			     int psize, int ssize);
+int htab_remove_mapping(unsigned long vstart, unsigned long vend,
+			int psize, int ssize);
 extern void add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages);
 extern void demote_segment_4k(struct mm_struct *mm, unsigned long addr);
 

arch/powerpc/mm/init_64.c

@@ -233,9 +233,6 @@ static void __meminit vmemmap_create_mapping(unsigned long start,
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
-extern int htab_remove_mapping(unsigned long vstart, unsigned long vend,
-			int psize, int ssize);
-
 static void vmemmap_remove_mapping(unsigned long start,
 				   unsigned long page_size)
 {