add consolenotifier for peripheral system alerts

pi/roverd/gpio_toggle.go

@@ -92,6 +92,10 @@ func (g *GPIOToggle) Configuration() GPIOToggleConfig {
 	return g.cfg
 }
 
+func (g *GPIOToggle) BackendDescription() string {
+	return "native GPIO"
+}
+
 func (g *GPIOToggle) setLocked(on bool) error {
 	// This is the only place a logical device state becomes an electrical GPIO
 	// value. Hardware that turns on when pulled low sets activeLow in roverd