ASoC: tegra: Fix kcontrol put callback in Mixer

The kcontrol put callback is expected to return 1 when there is change
in HW or when the update is acknowledged by driver. This would ensure
that change notifications are sent to subscribed applications. Filter
out duplicate updates in Mixer driver.

Fixes: 05bb3d5e

 ("ASoC: tegra: Add Tegra210 based Mixer driver")
Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Suggested-by: Jaroslav Kysela <perex@perex.cz>
Suggested-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/1637219231-406-17-git-send-email-spujar@nvidia.com
Signed-off-by: Mark Brown <broonie@kernel.org>