tmem: Retire XEN_SYSCTL_TMEM_OP_[SET_CAP|SAVE_GET_CLIENT_CAP]

It is not used by anything. Its intent was to complement
the 'weight' attribute but there hadn't been any request for this.

If there is a need to resurface it, it can be integrated back
via the XEN_SYSCTL_TMEM_SET_CLIENT_INFO introduced in
"tmem/libxc: Squash XEN_SYSCTL_TMEM_OP_[SET|SAVE].."

Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

tools/python/xen/lowlevel/xc/xc.c

@@ -1641,7 +1641,6 @@ static PyObject *pyxc_tmem_control(XcObject *self,
         case XEN_SYSCTL_TMEM_OP_FREEZE:
         case XEN_SYSCTL_TMEM_OP_DESTROY:
         case XEN_SYSCTL_TMEM_OP_SET_WEIGHT:
-        case XEN_SYSCTL_TMEM_OP_SET_CAP:
         case XEN_SYSCTL_TMEM_OP_SET_COMPRESS:
         default:
             break;