FMCOMMS1: Make the DAC cal update right away, not when you hit the "apply" button

Signed-off-by: Robin Getz <Robin.Getz@analog.com>
SCPI: Add a little for helping with the Tx cal on the FMCOMMS1

Signed-off-by: Robin.Getz <Robin.Getz@analog.com>
FMCOMMS1: First draft of Tx calibration

Signed-off-by: Robin Getz <robin.getz@analog.com>