media: adv7511-v4l2: correctly report EDIDs of 1 block

If the EDID has an odd number of blocks (usually just 1, but the
same problem occurs with 3 blocks), then VIDIOC_G_EDID reported 2
(or 4) blocks. Fix this.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>