drm/imx/dcss: Replace module initialization with DRM helpers

Replace module_platform_driver() with drm_module_platform_driver(). The
DRM macro respects drm_firmware_drivers_only() and fails if the flag has
been set.

Signed-off-by: Javier Martinez Canillas <[e-mail]>
Reviewed-by: Lucas Stach <[e-mail]>
Acked-by: Thomas Zimmermann <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/imx/dcss/dcss-drv.c

···
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/platform_device.h>
+#include <drm/drm_module.h>
 #include <drm/drm_of.h>
 
 #include "dcss-dev.h"
···
 	},
 };
 
-module_platform_driver(dcss_platform_driver);
+drm_module_platform_driver(dcss_platform_driver);
 
 MODULE_AUTHOR("Laurentiu Palcu <[e-mail]>");
 MODULE_DESCRIPTION("DCSS driver for i.MX8MQ");