arm64: dts: rockchip: remove hclk from dsi node on rk356x

The hclk is not used in the dw-mipi-dsi binding,
so remove hclk from the rk356x.dtsi dsi node.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Link: https://lore.kernel.org/r/4df211eb-4fcd-ee20-48a1-ce7712de552c@gmail.com


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