drm/fb helper: don't call drm_helper_connector_dpms directly

Yet again a case where the fb helper is too intimate with the crtc
helper and calls a crtc helepr function directly instead of going
through the interface vtable.

This fixes console blanking in drm/i915 with the new i915-specific
modeset code.

Reported-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Tested-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_fb_helper.c

@@ -330,7 +330,7 @@ static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
 		/* Walk the connectors & encoders on this fb turning them on/off */
 		for (j = 0; j < fb_helper->connector_count; j++) {
 			connector = fb_helper->connector_info[j]->connector;
-			drm_helper_connector_dpms(connector, dpms_mode);
+			connector->funcs->dpms(connector, dpms_mode);
 			drm_connector_property_set_value(connector,
 				dev->mode_config.dpms_property, dpms_mode);
 		}