powerpc/configs: Drop REISERFS from pseries & powernv

No one uses reiserfs much these days, or is likely to in future. So drop
it from pseries and powernv defconfigs to save time and space. It's
still enabled in ppc64_defconfig so we get some build coverage.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2 files changed