[media] adv7842: increase wait time

Wait 5ms after main reset. The data-sheet doesn't specify the wait
after i2c-controlled reset, so using same value as after pin-controlled
reset.

Signed-off-by: Martin Bugge <marbugge@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>