AD936x - TX Power depends on Sample Rate

[xdch47]

For the AD936x / FMCOMM5 gain reduction by -6dbm can be observed, when switching sample rates > 20 MHz to < 20 MHz.

See https://github.com/analogdevicesinc/pyadi-iio/issues/591, for details.

This seems the original source of the copied filter coefficients. (https://github.com/analogdevicesinc/libad9361-iio/blob/main/ad9361_baseband_auto_rate.c#L30)