Break CFM out into its own sensor

Break CFM out into its own sensor to be the System Airflow
sensor. Also change CFM calculation to use rpm instead of pwm
as it is more accurate.

Change-Id: Ic152465f8c0cd9256176b6a673f121562cff8580
Signed-off-by: James Feist <james.feist@linux.intel.com>
2 files changed