dt-bindings: phy-rockchip-inno-dsidphy: add compatible for rk3568

Add a compatible string for the rk3568 dsi-dphy.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20220919164616.12492-2-macroalpha82@gmail.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>