Add reset handler which gets host value of PMCR_EL0 and make writable
bits architecturally UNKNOWN except PMCR.E which is zero. Add an access
handler for PMCR.
Signed-off-by: NShannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: NAndrew Jones <drjones@redhat.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>