[media] pwc: Add v4l2 controls for pan/tilt on Logitech QuickCam Orbit/Sphere

This makes the API for this:
1) v4l2 spec compliant
2) match that of the UVC Logitech QuickCam Sphere models

For now this operates in parellel to the sysfs interface for this, but the
intend is to deprecate the sysfs interface and remove it.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>