sainsmart-dds120: make the "1kHz" reference signal 1kHz
sainsmart-dds120: make the "1kHz" reference signal 1kHz

swegener/sigrok-firmware-fx2lafw,swegener/sigrok-firmware-fx2lafw,uffejakobsen/sigrok-firmware-fx2lafw,uffejakobsen/sigrok-firmware-fx2lafw,swegener/sigrok-firmware-fx2lafw,swegener/sigrok-firmware-fx2lafw,uffejakobsen/sigrok-firmware-fx2lafw,uffejakobsen/sigrok-firmware-fx2lafw