The quantization bits are in bits 7-6, not 7-4, so shift by 6 instead of 4.

This bug is caused by a typo in the adv7511 datasheet.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>