drm/fb-helper: Cleanup include statements in header file

Only include what we have to.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-12-tzimmermann@suse.de

include/drm/drm_fb_helper.h

@@ -32,11 +32,9 @@
 
 struct drm_fb_helper;
 
-#include <drm/drm_client.h>
-#include <drm/drm_crtc.h>
-#include <drm/drm_device.h>
 #include <linux/fb.h>
-#include <linux/kgdb.h>
+
+#include <drm/drm_client.h>
 
 enum mode_set_atomic {
 	LEAVE_ATOMIC_MODE_SET,