OMAPDSS: APPLY: Remove omap_dss_device references from dss_ovl_enable/disable

An overlay isn't allowed to be enabled/disabled if it isn't connected to an
omap_dss_device. This requirement isn't needed any more. An overlay can be
enabled/disabled as long as it has an output connected to it. The output may
not be connected to a device, but we can be assured that the connected
manager's output is in use by an output interface.
Signed-off-by: Archit Taneja <archit@ti.com>

drivers/video/omap2/dss/apply.c

@@ -1464,7 +1464,7 @@ int dss_ovl_enable(struct omap_overlay *ovl)
 		goto err1;
 	}
 
-	if (ovl->get_device(ovl) == NULL) {
+	if (ovl->manager == NULL || ovl->manager->output == NULL) {
 		r = -EINVAL;
 		goto err1;
 	}
@@ -1514,7 +1514,7 @@ int dss_ovl_disable(struct omap_overlay *ovl)
 		goto err;
 	}
 
-	if (ovl->get_device(ovl) == NULL) {
+	if (ovl->manager == NULL || ovl->manager->output == NULL) {
 		r = -EINVAL;
 		goto err;
 	}