drm/dp_mst: Rename drm_dp_add_port and drm_dp_update_port

The names for these functions are rather confusing. drm_dp_add_port()
sounds like a function that would simply create a port and add it to a
topology, and do nothing more. Similarly, drm_dp_update_port() would be
assumed to be the function that should be used to update port
information after initial creation.

While those assumptions are currently correct in how these functions are
used, a quick glance at drm_dp_add_port() reveals that drm_dp_add_port()
can also update the information on a port, and seems explicitly designed
to do so. This can be explained pretty simply by the fact that there's
more situations that would involve updating the port information based
on a link address response as opposed to a connection status
notification than the driver's initial topology probe. Case in point:
reprobing link addresses after suspend/resume.

Since we're about to start using drm_dp_add_port() differently for
suspend/resume reprobing, let's rename both functions to clarify what
they actually do.

Cc: Juston Li <juston.li@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Harry Wentland <hwentlan@amd.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20190903204645.25487-18-lyude@redhat.com

drivers/gpu/drm/drm_dp_mst_topology.c

@@ -1903,7 +1903,8 @@ void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
 }
 EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
 
-static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
+static void
+drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
 				    struct drm_device *dev,
 				    struct drm_dp_link_addr_reply_port *port_msg)
 {
@@ -2008,7 +2009,8 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
 	drm_dp_mst_topology_put_port(port);
 }
 
-static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
+static void
+drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
 			    struct drm_dp_connection_status_notify *conn_stat)
 {
 	struct drm_dp_mst_port *port;
@@ -2457,7 +2459,8 @@ static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
 	drm_dp_check_mstb_guid(mstb, reply->guid);
 
 	for (i = 0; i < reply->nports; i++)
-		drm_dp_add_port(mstb, mgr->dev, &reply->ports[i]);
+		drm_dp_mst_handle_link_address_port(mstb, mgr->dev,
+						    &reply->ports[i]);
 
 	drm_kms_helper_hotplug_event(mgr->dev);
 
@@ -3317,7 +3320,7 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
 	}
 
 	if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
-		drm_dp_update_port(mstb, &msg.u.conn_stat);
+		drm_dp_mst_handle_conn_stat(mstb, &msg.u.conn_stat);
 
 		DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
 			      msg.u.conn_stat.port_number,