ARM: dts: msm: Add APM device node for MSMTITANIUM

Add the Array Power Mux(APM) controller device node to
enable the selection of MX or APCC rails as the voltage
source for CPU and cache memory arrays.

Change-Id: I0750714cb3cadcdabb04aa6c7985d632b7d01a2a
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>