Add Stonewither OpenPOWER system layer

This system uses much of the same hardware as Witherspoon,
but not have any power supplies or fans in the chassis.  As such,
it includes the meta-witherspoon layer and points to the Witherspoon
device tree and MRW XML.

A future commit will fully remove fan and power supply
monitoring.

Change-Id: I1c7f7da66b306f3c30eb955a63121cc3f62f663a
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
8 files changed