ASoC: siu: Add MODULE_FIRMWARE macro

The module loads firmware so add a MODULE_FIRMWARE macro to provide that
information via modinfo.
Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Link: https://lore.kernel.org/r/20230613095454.38696-1-juerg.haefliger@canonical.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sh/siu_dai.c

@@ -796,3 +796,5 @@ module_platform_driver(siu_driver);
 MODULE_AUTHOR("Carlos Munoz <carlos@kenati.com>");
 MODULE_DESCRIPTION("ALSA SoC SH7722 SIU driver");
 MODULE_LICENSE("GPL");
+
+MODULE_FIRMWARE("siu_spb.bin");