The Tevii S480 outputs 18V on startup for the LNB supply voltage and does not
automatically power down. This blocks other receivers connected
to a satellite channel router (EN50494), since the receivers can not send the
required DiSEqC sequences when the Tevii card is connected to a the same SCR.

This patch switches off the LNB supply voltage on initialization of the frontend.

[mchehab@osg.samsung.com: add a comment about why we're explicitly
 turning off voltage at device init]
Cc: stable@vger.kernel.org
Signed-off-by: Ulrich Eckhardt <uli@uli-eckhardt.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>