KVM: x86/pmu: Move reprogram_counters() to pmu.h

Move reprogram_counters() out of Intel specific PMU code and into pmu.h so
that it can be used to implement AMD PMU v2 support.

No functional change intended.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Like Xu <likexu@tencent.com>
[sean: rewrite changelog]
Link: https://lore.kernel.org/r/20230603011058.1038821-3-seanjc@google.com


Signed-off-by: Sean Christopherson <seanjc@google.com>