usb: dwc2: Fix interval type issue

The maximum value that unsigned char can hold is 255, meanwhile
the maximum value of interval is  2^(bIntervalMax-1)=2^15.

Signed-off-by: Grigor Tovmasyan <tovmasya@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/core.h

@@ -217,7 +217,7 @@ struct dwc2_hsotg_ep {
 	unsigned char           dir_in;
 	unsigned char           index;
 	unsigned char           mc;
-	unsigned char           interval;
+	u16                     interval;
 
 	unsigned int            halted:1;
 	unsigned int            periodic:1;