usb: cdns3: gadget: use unsigned int for 32-bit number

If it is 'int', it can't stands for the highest bit for 32-bit
number, since the largest 'int' is 0x7fffffff.
Reviewed-by: NJun Li <jun.li@nxp.com>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>
Acked-by: NRoger Quadros <rogerq@ti.com>
Link: https://lore.kernel.org/r/20200623031001.8469-4-peter.chen@nxp.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/cdns3/gadget.c

@@ -1809,7 +1809,7 @@ static irqreturn_t cdns3_device_thread_irq_handler(int irq, void *data)
 	struct cdns3_device *priv_dev = data;
 	irqreturn_t ret = IRQ_NONE;
 	unsigned long flags;
-	int bit;
+	unsigned int bit;
 	unsigned long reg;
 
 	spin_lock_irqsave(&priv_dev->lock, flags);