ASoC: cs42l73: Don't mix SNDRV_PCM_RATE_KNOT with specific rates

SNDRV_PCM_RATE_KNOT means that the device can support rates that can not be
expressed using the rate bits. The driver will provide a list of those rates
specified through constraints. Any rate bits that are set in the rates mask will
be ignored. So setting other rate bits besides SNDRV_PCM_RATE_KNOT wont have any
effect, but might be confusing to the casual reader, so remove them.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Brian Austin <brian.austin@cirrus.com>
Signed-off-by: Mark Brown <broonie@linaro.org>