media: dt-bindings: i2c: toshiba,et8ek8: Convert to DT schema

media: dt-bindings: i2c: toshiba,et8ek8: Convert to DT schema

Convert binding for toshiba,et8ek8 from TXT to YAML format.
Update MAINTAINERS file accordingly. The binding references
video-interface-devices.yaml at top level to inherit flash-leds
property.

Signed-off-by: Alex Tran <alex.t.tran@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>