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

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

Change-Id: Ibe317015a79fdc8e8f1c0b648715339e0b43aebf
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>