usb: dwc2: gadget: report disconnection after reset

If usb bus is reset without a physical disconnection, all endpoints
will remain open. Call s3c_hsotg_disconnect() from reset handler to
report a disconnect to gadget framework. hsotg->connected is checked
in s3c_hsotg_disconnect() before processing disconnect.

In some cases, USBRst is seen before EnumDone and after it as well.
So move setting of hsotg->connected to set-address to avoid reporting
extra disconnection in this case.

Tested-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>