dt-bindings: soc: rockchip: add rk3576 usb2phy syscon

The usb2phy is accessible via a syscon registers on RK3576, similar
to RK3588.

Signed-off-by: Frank Wang <frank.wang@rock-chips.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20241016073713.14133-2-frawang.cn@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Author: Frank Wang

Documentation/devicetree/bindings/soc/rockchip/grf.yaml

@@ -81,6 +81,7 @@ properties:
               - rockchip,rk3568-pmugrf
               - rockchip,rk3576-ioc-grf
               - rockchip,rk3576-pmu0-grf
+              - rockchip,rk3576-usb2phy-grf
               - rockchip,rk3588-usb2phy-grf
               - rockchip,rv1108-grf
               - rockchip,rv1108-pmugrf
@@ -234,6 +235,7 @@ allOf:
               - rockchip,rk3308-usb2phy-grf
               - rockchip,rk3328-usb2phy-grf
               - rockchip,rk3399-grf
+              - rockchip,rk3576-usb2phy-grf
               - rockchip,rk3588-usb2phy-grf
               - rockchip,rv1108-grf