video: pxa168fb: Cleanup pxa168fb.h file

Remove incorrect file reference in comments section.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

include/video/pxa168fb.h

 /*
- * linux/arch/arm/mach-mmp/include/mach/pxa168fb.h
- *
  *  Copyright (C) 2009 Marvell International Ltd.
  *
  * This program is free software; you can redistribute it and/or modify