x86: enable CMT for each domain RMID

x86: enable CMT for each domain RMID

If the CMT service is attached to a domain, its related RMID
will be set to hardware for monitoring when the domain's vcpu is
scheduled in. When the domain's vcpu is scheduled out, RMID 0
(system reserved) will be set for monitoring.

Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>