CVE-2023-53361

In the Linux kernel, the following vulnerability has been resolved:

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 501b81046701
("mips: mm: add p?d_leaf() definitions") add p?d_leaf() definition for
LoongArch.