arm: omap: board-cm-t35: use generic dpi panel's gpio handling

The cm-t35 board file currently requests gpios required to configure the tdo35s
panel, and provides platform_enable/disable callbacks to configure them.

These tasks have been moved to the generic dpi panel driver itself and shouldn't
be done in the board files.

Remove the gpio requests and the platform callbacks from the board file.
Add the gpio information to generic dpi panel's platform data so that it's
passed to the panel driver.

Note: Only BL enable gpio is handled in the panel driver. The LCD enable
GPIO is handled in the board file at init time, as there's a 50 ms delay
required when using the GPIO, and the panel driver doesn't know about
that.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>