rx front end control register 2
| FAGC_GAIN | fine agc gain. |
| FAGC_INI_VAL | fagc gain initial value |
| CNR_IDX_DELTA | cnr index delta. |
| FAGC_REF | fine agc signal reference. |
| CORDIC_MIN_VIN_TH | cordic input signal min threshold |
| FREQ_TRADE_EN | enable frequency trade when cordic input signal small than cordic_min_vin_th |
| CHN_SHIFT | channel filter shift |