KVM: arm: rename pm_fake handler to trap_raz_wi

KVM: arm: rename pm_fake handler to trap_raz_wi

pm_fake doesn't quite describe what the handler does (ignoring writes
and returning 0 for reads).

As we're about to use it (a lot) in a different context, rename it
with a (admitedly cryptic) name that make sense for all users.

Signed-off-by: Zhichao Huang <[email protected]>
Reviewed-by: Alex Bennee <[email protected]>
Acked-by: Christoffer Dall <[email protected]>
Acked-by: Marc Zyngier <[email protected]>
Signed-off-by: Alex Bennée <[email protected]>
Signed-off-by: Christoffer Dall <[email protected]>