x86/mm/pageattr: Add a PTE pagetable populating function

Handle last level by unconditionally writing the PTEs into the PTE page
while paying attention to the NX bit.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

diff --cc arch/x86/mm/pageattr.c
Simple merge