[kernel][mutex][trace] Add ktracing for kernel mutex events. (kernel)

Add ktracing for kernel mutex events; defaulted to off at compile time.

Note: this CL only adds trace definitions and tracing behavior to the
kernel.  To make any use of these events, a follow up change which
implementes the trace importer behavior is needed.

Change-Id: Ia759ff3a62cb0593fa269963a7959b17aabedd24