usb: dwc3: pci: Fix dr_mode misspelling

usb_get_dr_mode() expects the device-property to be spelled
"dr_mode" not "dr-mode".

Spelling it properly fixes the following warning showing up in dmesg:
[ 8704.500545] dwc3 dwc3.2.auto: Configuration mismatch. dr_mode forced to gadget

Signed-off-by: Hans de Goede <hdegoede@redhat.com
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/dwc3-pci.c

@@ -115,7 +115,7 @@ static int dwc3_pci_quirks(struct dwc3_pci *dwc)
 		int ret;
 
 		struct property_entry properties[] = {
-			PROPERTY_ENTRY_STRING("dr-mode", "peripheral"),
+			PROPERTY_ENTRY_STRING("dr_mode", "peripheral"),
 			{ }
 		};