drm/panel: panel-dsi-cm: drop unneeded includes

Drop unneeded includes.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201215104657.802264-74-tomi.valkeinen@ti.com

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

@@ -11,8 +11,6 @@
 #include <linux/gpio/consumer.h>
 #include <linux/jiffies.h>
 #include <linux/module.h>
-#include <linux/sched/signal.h>
-#include <linux/slab.h>
 #include <linux/of_device.h>
 #include <linux/regulator/consumer.h>