ARM: dts: msm: Add ipc-spinlock entry for msmtitanium

Add the ipc-spinlock entry to facilitate locking between apps and
non-apps processors.

Change-Id: Ic0908e58bedb46ea2d4841b49ad18d9596146b97
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>