ASoC: codecs: wcd937x: make stub functions inline

For some reason we ended up with stub functions that are not inline,
this can result in build error if its included multiple places, as we will
be redefining the same function

Fixes: c99a515 ("ASoC: codecs: wcd937x-sdw: add SoundWire driver")
Cc: Stable@vger.kernel.org
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>
Link: https://patch.msgid.link/20250909121954.225833-3-srinivas.kandagatla@oss.qualcomm.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: Srinivas Kandagatla

sound/soc/codecs/wcd937x.h

@@ -552,21 +552,21 @@ int wcd937x_sdw_hw_params(struct wcd937x_sdw_priv *wcd,
 struct device *wcd937x_sdw_device_get(struct device_node *np);
 
 #else
-int wcd937x_sdw_free(struct wcd937x_sdw_priv *wcd,
+static inline int wcd937x_sdw_free(struct wcd937x_sdw_priv *wcd,
 		     struct snd_pcm_substream *substream,
 		     struct snd_soc_dai *dai)
 {
 	return -EOPNOTSUPP;
 }
 
-int wcd937x_sdw_set_sdw_stream(struct wcd937x_sdw_priv *wcd,
+static inline int wcd937x_sdw_set_sdw_stream(struct wcd937x_sdw_priv *wcd,
 			       struct snd_soc_dai *dai,
 			       void *stream, int direction)
 {
 	return -EOPNOTSUPP;
 }
 
-int wcd937x_sdw_hw_params(struct wcd937x_sdw_priv *wcd,
+static inline int wcd937x_sdw_hw_params(struct wcd937x_sdw_priv *wcd,
 			  struct snd_pcm_substream *substream,
 			  struct snd_pcm_hw_params *params,
 			  struct snd_soc_dai *dai)