selftests: alsa: Start validating control names

Not much of a test but we keep on getting problems with boolean controls
not being called Switches so let's add a few basic checks to help people
spot problems.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220421115020.14118-1-broonie@kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>