drm/omap: use true,false for bool variable

Fixes coccicheck warning:

drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c:681:1-15: WARNING: Assignment of 0/1 to bool variable
drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c:732:1-15: WARNING: Assignment of 0/1 to bool variable
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NZheng Bin <zhengbin13@huawei.com>
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1579763123-62749-1-git-send-email-zhengbin13@huawei.com

drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c

@@ -678,7 +678,7 @@ static int dsicm_power_on(struct panel_drv_data *ddata)
 	if (r)
 		goto err;
 
-	ddata->enabled = 1;
+	ddata->enabled = true;
 
 	if (!ddata->intro_printed) {
 		dev_info(&ddata->pdev->dev, "panel revision %02x.%02x.%02x\n",
@@ -729,7 +729,7 @@ static void dsicm_power_off(struct panel_drv_data *ddata)
 	if (ddata->vpnl)
 		regulator_disable(ddata->vpnl);
 
-	ddata->enabled = 0;
+	ddata->enabled = false;
 }
 
 static int dsicm_panel_reset(struct panel_drv_data *ddata)