KVM: x86/vPMU: rename a few PMU functions

Before introducing a pmu.h header for them, make the naming more
consistent.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 9dadf8d..9d69f76 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -111,7 +111,7 @@
 	/* Update physical-address width */
 	vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
 
-	kvm_pmu_cpuid_update(vcpu);
+	kvm_pmu_refresh(vcpu);
 	return 0;
 }