Add 'DDS Sample Rate Offset' control. Allows values in Hz from -5000 to +5000.
The value is added to the nominal sample rate and written to the DDS register.
Signed-off-by: NJulian Cable <julian_cable@yahoo.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@suse.cz>