powerpc: Exported functions __clear_user and copy_page use r2 so need _GLOBAL_TOC()

__clear_user and copy_page load from the TOC and are also exported
to modules. This means we have to use _GLOBAL_TOC() so that we
create the global entry point that sets up the TOC.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/lib/copypage_64.S

@@ -16,7 +16,7 @@ PPC64_CACHES:
         .tc             ppc64_caches[TC],ppc64_caches
         .section        ".text"
 
-_GLOBAL(copy_page)
+_GLOBAL_TOC(copy_page)
 BEGIN_FTR_SECTION
 	lis	r5,PAGE_SIZE@h
 FTR_SECTION_ELSE

arch/powerpc/lib/string_64.S

@@ -77,7 +77,7 @@ err3;	stb	r0,0(r3)
 	mr	r3,r4
 	blr
 
-_GLOBAL(__clear_user)
+_GLOBAL_TOC(__clear_user)
 	cmpdi	r4,32
 	neg	r6,r3
 	li	r0,0