arm/dt: msm8974: add ipc-spinlock entry

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

Note that on v1 the dedicated spinlock hardware is defective, so use the
ldrex implementation as a workaround.

Change-Id: I126114c572530a62f4a487c9a012976ca8266d25
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
2 files changed