pinctrl: pinctrl-imx6q: add missed mux function for USBOTG_ID

The original pin registers table is derived from u-boot mainline,
but somehow it was found missing some mux functions for USBOTG_ID.
We added it at the bottom by following the exist pin function ids,
then it will not break the exist using of pin function id in dts file.

Reported-by: Richard Zhao <richard.zhao@freescale.com>
Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>