usb: dwc2: Add support for v3 snpsid value

This has been tested to the extent that I can enumerate
a asix usb networking adapter and boot a kernel over usb
on the 96boards hikey u-boot port I'm currently doing.

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>

drivers/usb/host/dwc2.c

@@ -932,7 +932,8 @@ int usb_lowlevel_init(int index, enum usb_init_type init, void **controller)
 	snpsid = readl(&regs->gsnpsid);
 	printf("Core Release: %x.%03x\n", snpsid >> 12 & 0xf, snpsid & 0xfff);
 
-	if ((snpsid & DWC2_SNPSID_DEVID_MASK) != DWC2_SNPSID_DEVID_VER_2xx) {
+	if ((snpsid & DWC2_SNPSID_DEVID_MASK) != DWC2_SNPSID_DEVID_VER_2xx &&
+	    (snpsid & DWC2_SNPSID_DEVID_MASK) != DWC2_SNPSID_DEVID_VER_3xx) {
 		printf("SNPSID invalid (not DWC2 OTG device): %08x\n", snpsid);
 		return -ENODEV;
 	}

drivers/usb/host/dwc2.h

@@ -732,6 +732,7 @@ struct dwc2_core_regs {
 #define DWC2_PCGCCTL_DEEP_SLEEP				(1 << 7)
 #define DWC2_PCGCCTL_DEEP_SLEEP_OFFSET			7
 #define DWC2_SNPSID_DEVID_VER_2xx			(0x4f542 << 12)
+#define DWC2_SNPSID_DEVID_VER_3xx			(0x4f543 << 12)
 #define DWC2_SNPSID_DEVID_MASK				(0xfffff << 12)
 #define DWC2_SNPSID_DEVID_OFFSET			12