V4L/DVB (5916): ivtv: fix pause/continue/play handling

Pausing a decoder followed by a Play command would do nothing. Fixed.
Pausing a decoder running at non-standard speed following by a Continue
would reset the speed to 100%. Fixed.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>