Introduce macro for PA_TO_PTE, setting the groundwork for future support
of various Arm VMSA extensions.
For extensions such as 52-bit VA/PA (FEAT_LPA2), the representation of
an address between a PTE and PA are not equivalent. This macro will
allow converting between the different representations.
Currently PA_TO_PTE is a NOP. Replace all instances where we go from PA
to PTE with new PA_TO_PTE macro.
Sponsored by: Arm Ltd