KVM: arm64: Tidying up PAuth code in KVM

Tidy up some of the PAuth trapping code to clear up some comments
and avoid clang/checkpatch warnings. Also, don't bother setting
PAuth HCR_EL2 bits in pKVM, since it's handled by the hypervisor.

Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20240722163311.1493879-1-tabba@google.com


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>