after days of ad9361 noise analysis with multiple borad, it turns out that the ad9361 RxFir can significantly reduce max noise level, with which the interference-to-noise ratio can be greatlt improved, and the nulling algotirhm can finally work properly; another experiment is about duifei multi rx channel phase-amplitude consistence, for which the rx external lo of ad9361 is enabled, but extra phase compensation is needed because the trace length of external lo is not matched
in dl814_k7_cal_coarse, change ant_clk to clk_96m, add rx_pre_test to verify nulling algorithm, with the ability to switch rx data between ad9361 data and test data
josh