riscv: Add support pte_protnone and pmd_protnone if CONFIG_NUMA_BALANCING

These two functions are used to distinguish between PROT_NONENUMA
protections and hinting fault protections.

Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>