[media] media: adv7180: increase delay after reset to 5ms

Initialization of the ADV7180 chip fails on the Renesas R8A7790-based
Lager board about 50% of the time.  This patch resolves the issue by
increasing the minimum delay after reset from 2 ms to 5 ms, following the
recommendation in the ADV7180 datasheet:

"Executing a software reset takes approximately 2 ms. However, it is
recommended to wait 5 ms before any further I2C writes are performed."

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>