V4L/DVB (11829): Rewrote frontend-attach mechanism to gain noise-less deactivation...

V4L/DVB (11829): Rewrote frontend-attach mechanism to gain noise-less deactivation of submodules

This patch is reorganizing the frontend-attach mechanism in order to
gain noise-less (superflous prints) deactivation of submodules.

Credits go to Uwe Bugla for helping to clean and test the code.

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>