V4L/DVB (13250): gspca - zc3xx: Add some delays and warn on i2c errors.

This patch fixes the kernel bug 14195 (random errors - bad images -
with the webcam 10fd:8050 - sensor tas5130cxx).

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>