V4L/DVB (13397): firedtv: move remote control workqueue handling into rc source file

Preparation for the port of firedtv to the firewire-core kernel API:
Canceling of the remote control workqueue job is factored into
firedtv-rc.c.  Plus trivial whitespace change.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>