video: vt8500: Remove unused platform_data/video-vt8500lcdfb.h

With the conversion to devicetree only for arch-vt8500, this
header is no longer required. This patch removes the #include
from the two framebuffer drivers that used it, and the header file.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Reviewed-by: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>