SCSC: Enable logging at startup rather than arming
GPS: Don't pass high GPS status to AP_Notify

AP_Notify only believes in fixes <= 3D so RTK etc must be mapped down
GPS: Fix glitch detector handling of high fix numbers

It previously tested for != 3D for bad fix, should be < 3D to
account for RTK fixes etc
Arming: Use <3D check for gps unhealthy rather than != 3D