Instead use vv->resources and video_drvdata(file) to
obtain this information.

This prepares for the vb2 conversion later when saa7146_fh is
dropped completely.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>