ALSA: aloop: Allow using global timers

Allow using global timers as a timer source when card id is equal to -1
in the timer_source parameter.

Signed-off-by: Ivan Orlov <[e-mail]>
Signed-off-by: Takashi Iwai <[e-mail]>
Link: https://patch.msgid.link/[e-mail]

sound/drivers/aloop.c

···
 			}
 		}
 	}
+	if (card_idx == -1)
+		tid->dev_class = SNDRV_TIMER_CLASS_GLOBAL;
 	if (!err && tid) {
 		tid->card = card_idx;
 		tid->device = dev;