drm: i2c: tda998x: Retry fetching the EDID if it fails first time.

drm: i2c: tda998x: Retry fetching the EDID if it fails first time.

Fetching the EDID from a connected monitor is an automated thing
with NXP TDA19988. But on some boards the fetching fails for the
first time silently without any indication that an error has occured.
More than that, subsequent fetches of the EDID succeed until the
monitor(s) are pluged out.

Add a function to validate the read EDID and retry if the block
retrieved is not valid.

Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>