ALSA: caiaq: Replace with __packed attribute

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

Link: https://lore.kernel.org/r/20231025132314.5878-7-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/caiaq/device.h

@@ -53,7 +53,7 @@ struct caiaq_device_spec {
 	unsigned char num_midi_out;
 	unsigned char num_midi_in;
 	unsigned char data_alignment;
-} __attribute__ ((packed));
+} __packed;
 
 struct snd_usb_caiaq_cb_info;