ARM: dts: imx6q-sabrelite: add usbmisc device

- add usbmisc device
- set property fsl,usbmisc for usb controllers
- set disable-over-current for imx6q-sabrelite usb otg

Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>