dt-bindings: soc: rockchip: add clock to RK3588 VO grf

The RK3588 VO GRF needs a clock. This adds the clock to the allowed
properties, makes it mandatory for the RK3588 VO grf and disallows it
for any other Rockchip grf.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20240213163609.44930-2-sebastian.reichel@collabora.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>