[media] DVB: dib0700, add support for Nova-TD LEDs

Add an override of read_status to intercept lock status. This allows
us to switch LEDs appropriately on and off with signal un/locked.

The second phase is to override sleep to properly turn off both.

This is a hackish way to achieve that.

Thanks to Mike Krufky for his help.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Patrick Boettcher <pboettcher@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>