usb: dwc3: of-simple: Add compatible for Spreadtrum SC9860 platform

Add compatible string to use this generic glue layer to support
Spreadtrum SC9860 platform's dwc3 controller.

Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c
index 4cef7d4..a26d1fd 100644
--- a/drivers/usb/dwc3/dwc3-of-simple.c
+++ b/drivers/usb/dwc3/dwc3-of-simple.c
@@ -177,6 +177,7 @@ static const struct of_device_id of_dwc3_simple_match[] = {
 	{ .compatible = "rockchip,rk3399-dwc3" },
 	{ .compatible = "xlnx,zynqmp-dwc3" },
 	{ .compatible = "cavium,octeon-7130-usb-uctl" },
+	{ .compatible = "sprd,sc9860-dwc3" },
 	{ /* Sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, of_dwc3_simple_match);