drm/omap: dsi: drop useless channel checks

A DSI peripheral can have virtual channel ID of 0-3. This should be
always the case, and there's no need in the driver to validate the
channel.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201215104657.802264-64-tomi.valkeinen@ti.com

drivers/gpu/drm/omapdrm/dss/dsi.c

@@ -3899,9 +3899,6 @@ static int dsi_update_channel(struct omap_dss_device *dssdev, int channel)
 	struct dsi_data *dsi = to_dsi_data(dssdev);
 	int r;
 
-	if (channel > 3)
-		return -EINVAL;
-
 	dsi_bus_lock(dsi);
 
 	if (!dsi->video_enabled) {
@@ -5065,12 +5062,8 @@ static int omap_dsi_host_attach(struct mipi_dsi_host *host,
 				struct mipi_dsi_device *client)
 {
 	struct dsi_data *dsi = host_to_omap(host);
-	unsigned int channel = client->channel;
 	int r;
 
-	if (channel > 3)
-		return -EINVAL;
-
 	if (dsi->dsidev) {
 		DSSERR("dsi client already attached\n");
 		return -EBUSY;
@@ -5120,10 +5113,6 @@ static int omap_dsi_host_detach(struct mipi_dsi_host *host,
 				struct mipi_dsi_device *client)
 {
 	struct dsi_data *dsi = host_to_omap(host);
-	unsigned int channel = client->channel;
-
-	if (channel > 3)
-		return -EINVAL;
 
 	if (WARN_ON(dsi->dsidev != client))
 		return -EINVAL;