[media] ad9389b: no monitor if EDID is wrong

state->have_monitor is set to false if the EDID that is read from
the monitor has too many segments or wrong CRC.

Signed-off-by: Mats Randgaard <matrandg@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>