V4L/DVB (10694): [PATCH] software IRQ watchdog for Flexcop B2C2 DVB PCI cards

With (some) Technisat cards you cannot run multiple DVB applications
in parallel and switch the channel at the same time.

There seems to be a problem on the interfaces or even inside the flexcop-device
that can't handle interruption on the streaming interface.

This patch adds a watchdog to check whether data is supposed to come in
(streaming PIDs are requested) and if no data is seen within 400ms (default) it
resets the streaming/pid-filtering hardware.

This patch is urgently needed to support the rev 2.8 of the hardware and solves
problem occassionally seen on older hardware.

Signed-off-by: Uwe Bugla <uwe.bugla@gmx.de>
Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>