KVM: x86/vPMU: introduce pmu.h header

This will be used for private function used by AMD- and Intel-specific
PMU implementations.

Signed-off-by: Wei Huang <wei@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --cc arch/x86/include/asm/kvm_host.h
Simple merge

diff --cc arch/x86/kvm/cpuid.c
Simple merge

diff --cc arch/x86/kvm/pmu.c
Simple merge

diff --cc arch/x86/kvm/pmu.h
Simple merge

diff --cc arch/x86/kvm/x86.c
Simple merge