illumos gate

In order for FMA to express disk health via the physical status LEDs on the Richmond-A hardware, we need to expose the internal mpt_sas SGPIO LED control functionality to libtopo. To do this, we need:

• A Private ioctl exposing LED control (both Set and Get actions) to userland.
• A libtopo Facility Provider module (a la fac_prov_ipmi) to hold the mapping from the LOCATE, SERVICE and OK2RM facility nodes to the underlying ioctl.