Improved a field description.

libraries/base/diag/diag.peripheral.yaml

@@ -39,7 +39,7 @@ peripherals:
               bit_offset: 0
               address_offset: 0x4
           - - field_name: freq
-              field_description: "Frequency of WG sinus, freq = int('frequency in 0 to 1' * f_clk * 2**width), where f_clk = f_adc in Hz."
+              field_description: "Frequency of WG sinus, freq = int('frequency in range 0 to 1' * f_adc * 2**width), where f_adc is sample frequency in Hz."
               width: 31
               bit_offset: 0
               address_offset: 0x8