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: Jun Li <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Acked-by: Roger Quadros <rogerq@ti.com>
Link: https://lore.kernel.org/r/20200623031001.8469-4-peter.chen@nxp.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>