soc: qcom: smp2p: Add unit test for remote spinlock PID tracking

New functionality has been added to track which processor owns a remote
spinlock when it is unable to be acquired.

Add a unit test for this functionality.

Change-Id: Iec182bd0defa9b970fd3b42aca21087f6e127b1b
Signed-off-by: Steven Cahail <scahail@codeaurora.org>