dt-bindings: soc: rockchip: add rk3566-pipe-grf compatible

The rk3566 requires special handling for the dwc3-otg clock in order for
the port to function correctly.
Add a binding for the rk3566-pipe-grf so we can handle setup with the
grf driver.

Signed-off-by: Peter Geis <pgwipeout@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220408151237.3165046-2-pgwipeout@gmail.com


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