OMAPFB: remove use of extended edid block

It seems that using the second EDID block causes more problems than is
of any help. The first mode in the extended block will get
FB_MODE_IS_FIRST set, which will override the first mode from the first
EDID block, thus making the default videomode selection not to work
properly.

This patch removes the use of the extended edid block for now.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>