ANDROID: KVM: arm64: Unallocated/Unhandled/Hidden sysreg access in pKVM

Use similar macros in pKVM as in other KVM modes for tracking the
handling of system registers. This is to make it clear whether
certain registers are deliberately not handled/hidden, as opposed
to being unallocated, and to bring the pKVM code more inline with
the rest of the system.

No functional change intended.

Signed-off-by: Fuad Tabba <tabba@google.com>
Bug: 278749606
Change-Id: I0b231bf13cc44887276c0ba9ed08ec7836155db2