KVM: arm64: Use KVM_REQ_RELOAD_PMU to handle PMCR_EL0.E change

Nested virt introduces yet another set of 'global' knobs for controlling
event counters that are reserved for EL2 (i.e. >= HPMN). Get ready to
share some plumbing with the NV controls by offloading counter
reprogramming to KVM_REQ_RELOAD_PMU.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241217175532.3658134-1-oliver.upton@linux.dev


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>