media: dt-bindings: Remove assigned-clock-* from various schema

Remove extraneous assigned-clock* from media/i2c/* schemas.

assigned-clock and assigned-clock-parent assume that there is a clock that
can be assigned and/or a clock parent that similarly can be assigned by
firmware which may not always be the case.

The sensor properties themselves should not mandate assigned-clock* as a
result.

Link: https://lore.kernel.org/linux-media/j7kgz2lyxnler5qwd7yiazdq6fmsv77kyozdrxf33h54ydakjz@uqjhwhoyv6re


Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>