video: pxa: Cleanup video-pxafb.h header

Commit 293b2da1 ("ARM: pxa: move platform_data definitions")
moved the file to the current location but forgot to remove the pointer
to its previous location. Clean it up.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

include/linux/platform_data/video-pxafb.h

 /*
- *  arch/arm/mach-pxa/include/mach/pxafb.h
- *
  *  Support for the xscale frame buffer.
  *
  *  Author:     Jean-Frederic Clere