ASoC: xilinx: Add missing module descriptions

Now that make W=1 starts complaining the lack of MODULE_DESCRIPTION(),
let's add the missing information.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/ZjpQm-hxLQtpgkUx@smile.fi.intel.comSigned-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Dragan Simic <dsimic@manjaro.org>
Link: https://lore.kernel.org/r/20240508091909.27062-8-tiwai@suse.deSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/xilinx/xlnx_formatter_pcm.c

@@ -721,5 +721,7 @@ static struct platform_driver xlnx_formatter_pcm_driver = {
 };
 
 module_platform_driver(xlnx_formatter_pcm_driver);
+
+MODULE_DESCRIPTION("ASoC driver for Xilinx audio formatter");
 MODULE_AUTHOR("Maruthi Srinivas Bayyavarapu <maruthis@xilinx.com>");
 MODULE_LICENSE("GPL v2");

sound/soc/xilinx/xlnx_i2s.c

@@ -253,6 +253,7 @@ static struct platform_driver xlnx_i2s_aud_driver = {
 
 module_platform_driver(xlnx_i2s_aud_driver);
 
+MODULE_DESCRIPTION("ASoC driver for Xilinx I2S audio");
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Praveen Vuppala  <praveenv@xilinx.com>");
 MODULE_AUTHOR("Maruthi Srinivas Bayyavarapu <maruthis@xilinx.com>");