Add get_streamparm and set_streamparm operations so subdrivers can
get/set stream parameters such as framerate.
Signed-off-by: NJim Paris <jim@jtan.com>
Signed-off-by: NJean-Francois Moine <moinejf@free.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>