dt-bindings: display: bridge: nwl-dsi: Add common properties

dt-bindings: display: bridge: nwl-dsi: Add common properties

Add common properties appearing in DTSes (assigned-clocks and others) to
fix dtbs_check warnings like:

  arch/arm64/boot/dts/freescale/imx8mq-evk.dt.yaml: mipi-dsi@30a00000:
    'assigned-clock-parents', 'assigned-clock-rates', 'assigned-clocks' do not match any of the regexes: '^panel@[0-9]+$', 'pinctrl-[0-9]+'

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200904145312.10960-3-krzk@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>