[media] adv7842: update RGB quantization range on HDMI/DVI-D mode irq

This was the reason for enabling the HDMI/DVI-D mode irq in the first place.

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>