KVM: arm64: Add kvm_vcpu_has_pmu() helper

mainline inclusion
from mainline-v5.11-rc1
commit 14bda7a9
bugzilla: https://gitee.com/openeuler/kernel/issues/I4NP0K
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=14bda7a927336055d7c0deb1483f9cdb687c2080



-------------------

There are a number of places where we check for the KVM_ARM_VCPU_PMU_V3
feature. Wrap this check into a new kvm_vcpu_has_pmu(), and use
it at the existing locations.

No functional change.

Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Jingyi Wang <wangjingyi11@huawei.com>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>