[media] adv7511: TX_EDID_PRESENT is still 1 after a disconnect

The V4L2_CID_TX_EDID_PRESENT control reports if an EDID is present.
The adv7511 however still reported the EDID present after disconnecting
the HDMI cable. Fix the logic regarding this control. And when the EDID
is disconnected also call ADV7511_EDID_DETECT to notify the bridge driver.
This was also missing.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: <stable@vger.kernel.org>      # for v3.12 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>