ARM: dts: msm: Add support for USB HS AC/DC coupling on SA8155

Enable USB_HS_AC_POLARITY(Active Low) and USB_HS_AC_EN bits in
USB2PHY_USB_PHY_AC_EN register of the USB2 PHYs on SA8155.
Also add pinctrl changes to configure GPIOs 113 and 123 in
USB2PHY AC ENABLE function mode.
This is required to enable USB HS AC/DC coupling feature.

Change-Id: Id29c40698096a9561a448a4798d01675eca5e751
Signed-off-by: Ajay Agarwal <ajaya@codeaurora.org>