ASoC: amd: simplify soundwire dependencies for legacy stack

The CONFIG_SOUNDWIRE_AMD is a user-visible option, it should be never
selected by another driver.
So replace the extra complexity with a normal Kconfig dependency in
SND_SOC_AMD_SOUNDWIRE.

Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Link: https://msgid.link/r/20240322112018.3063344-1-Vijendar.Mukunda@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>