LoongArch: mm: Add p?d_leaf() definitions

When I do LTP test, LTP test case ksm06 caused panic at
	break_ksm_pmd_entry
	  -> pmd_leaf (Huge page table but False)
	  -> pte_present (panic)

The reason is pmd_leaf() is not defined, So like commit 501b8104
("mips: mm: add p?d_leaf() definitions") add p?d_leaf() definition for
LoongArch.

Fixes: 09cfefb7 ("LoongArch: Add memory management")
Cc: stable@vger.kernel.org
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Hongchen Zhang <zhanghongchen@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

arch/loongarch/include/asm/pgtable.h

@@ -593,6 +593,9 @@ static inline long pmd_protnone(pmd_t pmd)
 }
 #endif /* CONFIG_NUMA_BALANCING */
 
+#define pmd_leaf(pmd)		((pmd_val(pmd) & _PAGE_HUGE) != 0)
+#define pud_leaf(pud)		((pud_val(pud) & _PAGE_HUGE) != 0)
+
 /*
  * We provide our own get_unmapped area to cope with the virtual aliasing
  * constraints placed on us by the cache architecture.