Uses the stats subsys to provide simple but useful debugging stats for
power management state changes and timing.
Removes the no longer needed PM_DEBUG config option
Replaces the use of PM_DEBUG for a test clock output pin for mec1501 and
adds in its place an SoC Kconfig option to enable it.
Adds a STATS_SET macro for assigning a value to a stat group field
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>