autonuma: make the AUTONUMA_SCAN_PMD_FLAG conditional to CONFIG_HAVE_ARCH_AUTONUMA_SCAN_PMD Remove the sysfs entry /sys/kernel/mm/autonuma/knuma_scand/pmd and force the knuma_scand pmd mode off if CONFIG_HAVE_ARCH_AUTONUMA_SCAN_PMD is not set by the architecture. Enable AutoNUMA for PPC64. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>