Applicable to AU/BU. The operating frequency in MHz.
(Replaces brzaccVLCurrentAUOperatingFrequency to support
a resolution of 0.5 MHz for units with HW revision C and higher).
For 5.8GHz products with SW version below 2.0 the range is
5740 to 5830 MHz using 10MHz resolution.
For units with SW version 2.0 and up the range is as defined
in the selected Sub Band.