Fix an oops during device initialization by correctly setting size_of_priv
instead of leaving it 0.
The regression was introduced by 8abe4a0a ("[media] dib7000:
export just one symbol") and only fixed for one type of dib0700 based
devices in 9e334c75 ("[media] Fix regression in some dib0700
based devices").

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=92301

Fixes: 8abe4a0a ("[media] dib7000: export just one symbol")

Cc: stable@vger.kernel.org # for version 3.17+
Signed-off-by: Thomas Reitmayr <treitmayr@devbase.at>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>