usb: chipidea: imx: add HSIC support

To support imx HSIC, there are some special requirement:
- The HSIC pad is 1.2v, it may need to supply from external
- The data/strobe pin needs to be pulled down first, and after
  host mode is initialized, the strobe pin needs to be pulled up
- During the USB suspend/resume, special setting is needed

Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Peter Chen <peter.chen@nxp.com>