drm/simpledrm: Do not include <drm/drm_plane_helper.h>

Remove unnecessary include statements for <drm/drm_plane_helper.h>.
The file contains helpers for non-atomic code and should not be
required by most drivers. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231204090852.1650-8-tzimmermann@suse.de

drivers/gpu/drm/tiny/simpledrm.c

@@ -25,7 +25,6 @@
 #include <drm/drm_gem_shmem_helper.h>
 #include <drm/drm_managed.h>
 #include <drm/drm_modeset_helper_vtables.h>
-#include <drm/drm_plane_helper.h>
 #include <drm/drm_probe_helper.h>
 
 #define DRIVER_NAME	"simpledrm"