ENGR00178932 USB: fix two USB otg common bug for i.MX6

ENGR00178932 USB: fix two USB otg common bug for i.MX6

 - Built in gadget device driver, plug in USB cable  with no response,
  the reason is USB VBUS wakeup is not enable after OTG switch,make
  sure pdata->port_enables is 1 even if the pdata is otg device pdata.

 -Without modprobe or built in  gadget device driver,after plug out
  the USB otg cable,will output "wait otg vbus change timeout!".The
  reason is we get error otgsc data  after USB enter low power mode.

Signed-off-by: make shi <b15407@freescale.com>