ASoC: simple-card-utils: Split simple_fixup_sample_fmt func

Split the simple_fixup_sample_fmt() into two functions by adding
one more function named simple_util_get_sample_fmt() to return
the sample format value.

This is useful for drivers that wish to simply get the sample format
without setting the mask.

Signed-off-by: Mohan Kumar <mkumard@nvidia.com>
Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Link: https://msgid.link/r/20240527125608.2461300-2-spujar@nvidia.com
Signed-off-by: Mark Brown <broonie@kernel.org>