V4L/DVB (3354e): bttv semaphore to mutex conversion

Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.

build-tested.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>