ppc/xive: Implement the XivePresenter interface

ppc/xive: Implement the XivePresenter interface

Each XIVE Router model, sPAPR and PowerNV, now implements the 'match_nvt'
handler of the XivePresenter QOM interface. This is simply moving code
and taking into account the new API.

To be noted that the xive_router_get_tctx() helper is not used anymore
when doing CAM matching and will be removed later on after other changes.

The XIVE presenter model is still too simple for the PowerNV machine
and the CAM matching algo is not correct on multichip system. Subsequent
patches will introduce more changes to scan all chips of the system.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20191125065820.927-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>