V4L/DVB (12260): em28xx: make support work for the Pinnacle Hybrid Pro (eb1a:2881)

Setup the GPIOs properly and enable support for the DVB side of the Pinnacle
Hybrid Pro USB stick.

Thanks to Andreas Lunderhage for testing patches and providing a remote debug
environment.

Cc: Andreas Lunderhage <lunderhage@home.se>
Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>