dt-bindings: soc: rockchip: add missing clock reference for rk3576-dcphy syscon

dt-bindings: soc: rockchip: add missing clock reference for rk3576-dcphy syscon

The rk3576 mipi dcphy syscon controls a clock, so needs to allow the
clock property. Add the missing entry in the list for it.

Fixes: 0e3f3d7c7ae3 ("dt-bindings: soc: rockchip: add rk3576 mipi dcphy syscon")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202508271156.z3wDB6bX-lkp@intel.com/
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20250828131107.3531769-1-heiko@sntech.de