T48: fix setting voltages from command line
T48 was using TL866A arrays for Vpp/Vcc when voltage is overridden using command line. Fix that, and while we are at it, add support for 21V and 25V Vpp
T48 was using TL866A arrays for Vpp/Vcc when voltage is overridden using command line. Fix that, and while we are at it, add support for 21V and 25V Vpp