[POWERPC] Fix sparse warnings in arch/powerpc/mm

Make two vmemmap helpers static in init_64.c
Make stab variables static in stab.c
Make psize defs static in hash_utils_64.c

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/mm/stab.c b/arch/powerpc/mm/stab.c
index efbbd13..60e6032 100644
--- a/arch/powerpc/mm/stab.c
+++ b/arch/powerpc/mm/stab.c
@@ -30,8 +30,8 @@
 };
 
 #define NR_STAB_CACHE_ENTRIES 8
-DEFINE_PER_CPU(long, stab_cache_ptr);
-DEFINE_PER_CPU(long, stab_cache[NR_STAB_CACHE_ENTRIES]);
+static DEFINE_PER_CPU(long, stab_cache_ptr);
+static DEFINE_PER_CPU(long, stab_cache[NR_STAB_CACHE_ENTRIES]);
 
 /*
  * Create a segment table entry for the given esid/vsid pair.