ALSA: aoa: Replace with __packed attribute

Replace the old __attribute__((packed)) with the new __packed.
Only cleanup, no functional changes.

Link: https://lore.kernel.org/r/20231025132314.5878-8-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/aoa/soundbus/i2sbus/interface.h

@@ -34,7 +34,7 @@ struct i2s_interface_regs {
 	__le32 peak_level_in1;	/* 0x90 */
 	PAD(12);
 	/* total size: 0x100 bytes */
-}  __attribute__((__packed__));
+} __packed;
 
 /* interrupt register is just a bitfield with
  * interrupt enable and pending bits */