ASoC: Mediatek: MT8183: TS3A227: fix build error

When building CONFIG_SND_SOC_MT8183_MT6358_TS3A227E_MAX98357A=m the
following error pops up:

../sound/soc/mediatek/mt8183/mt8183-mt6358-ts3a227-max98357.c: In function ‘mt8183_mt6358_ts3a227_max98357_dev_probe’:
../sound/soc/mediatek/mt8183/mt8183-mt6358-ts3a227-max98357.c:325:13: error: ‘struct snd_soc_dai_link’ has no member named ‘platform’; did you mean ‘platforms’?
   dai_link->platform = NULL;
             ^~~~~~~~
             platforms

Rework to use 'dai_link->platforms' instead of 'dai_link->platform'.

Fixes: 11c02690 ("ASoC: Mediatek: MT8183: Add machine driver with TS3A227")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/mediatek/mt8183/mt8183-mt6358-ts3a227-max98357.c

@@ -322,7 +322,7 @@ mt8183_mt6358_ts3a227_max98357_dev_probe(struct platform_device *pdev)
 		 * the "platform" will not null when probe is trying
 		 * again. It's not expected normally.
 		 */
-		dai_link->platform = NULL;
+		dai_link->platforms = NULL;
 
 		if (dai_link->platform_name)
 			continue;