arm64: KVM: Fix perf cycle counter support for VHE

arm64: KVM: Fix perf cycle counter support for VHE

The kvm_vcpu_pmu_{read,write}_evtype_direct functions do not handle
the cycle counter use-case, this leads to inaccurate counts and a
WARN message when using perf with the cycle counter (-e cycle).

Let's fix this by adding a use case for pmccfiltr_el0.

Fixes: 7909cff57188 ("arm64: KVM: Avoid isb's by using direct pmxevtyper sysreg")
Reported-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>