KVM: VMX: Rename VMX functions to conform to kvm_x86_ops names

Massage VMX's implementation names for kvm_x86_ops to maximize use of
kvm-x86-ops.h.  Leave cpu_has_vmx_wbinvd_exit() as-is to preserve the
cpu_has_vmx_*() pattern used for querying VMCS capabilities.  Keep
pi_has_pending_interrupt() as vmx_dy_apicv_has_pending_interrupt() does
a poor job of describing exactly what is being checked in VMX land.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220128005208.4008533-14-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>