ALSA: ac97: bus: Add missing module description

Now that make W=1 starts complaining the lack of MODULE_DESCRIPTION(),
let's add the missing information.

Reported-by: Andy Shevchenko <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]
Signed-off-by: Takashi Iwai <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Dragan Simic <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: tiwai

sound/ac97/bus.c

@@ -551,5 +551,6 @@ static void __exit ac97_bus_exit(void)
 }
 module_exit(ac97_bus_exit);
 
+MODULE_DESCRIPTION("AC97 bus interface");
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Robert Jarzmik <[email protected]>");