drm/msm: Use drm_connector_has_possible_encoder()

Use drm_connector_has_possible_encoder() for checking
whether the encoder has an associated connector.

v2: Replace the drm_for_each_connector_encoder_ids() loop
    with a simple drm_connector_has_possible_encoder() call

Cc: Rob Clark <robdclark@gmail.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180628131315.14156-9-ville.syrjala@linux.intel.com
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/msm/dsi/dsi_manager.c

@@ -751,12 +751,8 @@ struct drm_connector *msm_dsi_manager_ext_bridge_init(u8 id)
 	connector_list = &dev->mode_config.connector_list;
 
 	list_for_each_entry(connector, connector_list, head) {
-		int i;
-
-		for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
-			if (connector->encoder_ids[i] == encoder->base.id)
-				return connector;
-		}
+		if (drm_connector_has_possible_encoder(connector, encoder))
+			return connector;
 	}
 
 	return ERR_PTR(-ENODEV);