[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>
3 files changed