KVM: x86: Move RDPID emulation intercept to its own enum

Add a dedicated intercept enum for RDPID instead of piggybacking RDTSCP.
Unlike VMX's ENABLE_RDTSCP, RDPID is not bound to SVM's RDTSCP intercept.

Fixes: fb6d4d34

 ("KVM: x86: emulate RDPID")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210504171734.1434054-5-seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>