ASoC: AMD: Add const to snd_soc_ops instances

Marking snd_soc_ops instances const

Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>