arm64: dts: agilex: use the compatible "intel,socfpga-agilex-hsotg"

The DWC2 USB controller on the Agilex platform does not support clock
gating, so use the chip specific "intel,socfpga-agilex-hsotg"
compatible.

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>