Add dedicated bindings for the Hisilicon Kirin 960 USB OTG Syscon,
to fully document the block and also fix dtbs_check warning:
hi3660-hikey960.dtb: usb3_otg_bc@ff200000: compatible: ['syscon', 'simple-mfd'] is too short
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240518204443.122586-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
