V4L/DVB (3403): Workaround to fix initialization for Nexus CA

Workaround for Nexus CA: Debi test fails unless first debi write is repeated.

Signed-off-by: Marco Schluessler <marco@lordzodiac.de>
Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>