arm/dt: msm9625: Add USB OTG and Android devices

Add device tree entries for the USB OTG and Android gadget devices.
Also update device tree documentation to reflect the required
'interrupt-names' property for HSUSB OTG devices.

Change-Id: Ie06251c8eb74a2af87a2e6f2e603270fb257b045
Signed-off-by: Jack Pham <jackp@codeaurora.org>