V4L/DVB (9780): dib0700: Stop repeating after user stops pushing button

A user noticed that there would continue to be 4-6 keypresses even after the
user stopped holding down the button.  This was because we were not reading
the bulk pipe faster than the firmware was injecting information, which would
result in a backlog.

Make the query interval faster, and increase the number of cycles before we
start repeating to compensate.

Thanks to Knud Poulsen <knud.poulsen@nokia.com> for pointing this out.

Signed-off-by: Devin Heitmueller <devin.heitmueller@gmail.com>
Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>