usb: cdns3: gadget: reset EP_CLAIMED flag while unloading

EP_CLAIMED flag is used to track the claimed endpoints. While unloading the
module, Reset EP_CLAIMED flag for all enabled endpoints. So that it can be
reused.

Signed-off-by: Sanket Parmar <sparmar@cadence.com>
Acked-by: Peter Chen <peter.chen@nxp.com>
Reviewed-by: Roger Quadros <rogerq@ti.com>
Acked-by: Felipe Balbi <balbi@kernel.org>
Link: https://lore.kernel.org/r/20191029122441.5816-1-sparmar@cadence.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>