powerpc/vdso: Remove vdso32_pages and vdso64_pages

vdso32_pages and vdso64_pages are not used anymore.

Remove them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bce021f616cbaf39dfb5766cf7ef114adcb918d9.1601197618.git.christophe.leroy@csgroup.eu