staging: olpc_dcon: olpc_dcon_xo_1.c: Switch to the gpio descriptor interface

Use the gpiod interface instead of the deprecated old non-descriptor
interface in olpc_dcon_xo_1.c.

Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>