KVM: arm64: pkvm: Make the ERR/ERX*_EL1 registers RAZ/WI

The ERR*/ERX* registers should be handled as RAZ/WI, and there
should be no need to involve EL1 for that.

Add a helper that handles such registers, and repaint the sysreg
table to declare these registers as RAZ/WI.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20211013120346.2926621-4-maz@kernel.org