Fix remaining issues with SG power supplies
Sorenson XG/SG Power Supply Driver
Mike Kucera says there's three (minor) issues with the Sorenson SG power supply:
- The "Clear LED" command returns an error.
- The trip status goes away when the output is turned on and then re-appears when the supply is turned off. It should reflect the external shutoff signal.
- We sometimes get a [57 -107] when turning on the supply. The supply does turn on, but the error is shown temporarily.