usb: gadget: udc: renesas_usb3: add USB ID signal monitoring

This usb 3.0 peripheral controller has a register (USB_OTG_STA) to monitor
the USB ID signal. So, this patch adds the ID signal monitoring to change
the mode to host (A-Host) or peripheral (B-Peripheral).
This patch also removes hardcoded setting as B-Peripheral mode.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>