ENGR00221217 usb: device: fix usb_state incorrect problem after pc sends resume

ENGR00221217 usb: device: fix usb_state incorrect problem after pc sends resume

At pc sends suspend/resume case, the udc_controller->usb_state should
keep unchange during the suspend/resume process, at former code, the
fsl_udc_resume set udc_controller->usb_state to USB_STATE_ATTACHED
unconditionally. In fact, USB_STATE_ATTACHED stands for initial state
and should be set when we try to run controller.

Signed-off-by: Peter Chen <peter.chen@freescale.com>