ASoC: soc-utils: allow sample rate up to 768kHz for the dummy dai

The dummy DAI should allow any (reasonable) rates possible.
Make the rate continuous for dummy and set range from 5512Hz to 768kHz

The change is mostly cosmetic as dummy is skipped when setting
the hwparams.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://patch.msgid.link/20240628120130.2015665-1-jbrunet@baylibre.com


Signed-off-by: Mark Brown <broonie@kernel.org>