arm64: dts: rockchip: add clocks to rk356x cru

The rk356x cru requires a 24m clock input to function. Add the clocks
properties to the cru to clear some dtbs_check warnings.

Signed-off-by: Peter Geis <pgwipeout@gmail.com>
Link: https://lore.kernel.org/r/20220511150117.113070-3-pgwipeout@gmail.com


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