dt-bindings: display: rockchip-vop: add additional properties

In the old txt situation we add/describe only properties that are used
by the driver/hardware itself. With yaml it also filters things in a
node that are used by other drivers like 'assigned-clocks' and
'assigned-clock-rates' for rk3399 and 'power-domains' for most
Rockchip Socs in 'vop' nodes, so add them to 'rockchip-vop.yaml'.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200403142235.8870-2-jbx6244@gmail.com