V4L/DVB (11885): Siano: Add new GPIO management interface

Add new GPIO management interface to replace old (buggy) one.
Keeping old interface intact for now.

Signed-off-by: Uri Shkolnik <uris@siano-ms.com>
Acked-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>