ARM: dts: msm: Switch to USB 2.0 for 8994 Interposer

USB 3.0 controller is currently not working correctly. Disable it
and enable the USB 2.0 controller.

Change-Id: I9772511bc2e6ac3e43c380604a26fa20317f7cfd
Signed-off-by: Jack Pham <jackp@codeaurora.org>