usb: dwc2: gadget: remove s3c_hsotg_ep_disable_force

Force argument is not used anymore. Clean up leftovers from
https://lkml.org/lkml/2014/12/9/283

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>