media: mali-c55: Bypass the Iridix Tonemap engine

media: mali-c55: Bypass the Iridix Tonemap engine

The Iridix Tonemap engine, if not bypassed, applies a digital gain
in order to compensate under-exposed images.

This however breaks the exposure and gain regulation performed on the
sensor.

If the Iridix Tonemap has to be used, it need to be supported in the
ISP uAPI and properly configured by userspace.

As the driver doesn't support it at the moment, bypass it by default.

Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>