V4L/DVB (8068): cx18: Add I2C slave reset via GPIO upon initialization

cx18: Add I2C slave reset via GPIO upon initialization.  One user,
Michael <msd4824@yahoo.com>, has reported this allows his HVR-1600 EEPROM to
be consistently recognized when using (long,) 100 msec delays.   The delays in
this commit are nominal (10 & 40 msec) and need testing/tuning on boards with
I2C problems to find the right values.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>