sound: irq: Remove IRQF_DISABLED

Since commit [e58aa3d2: genirq: Run irq handlers with interrupts disabled],
We run all interrupt handlers with interrupts disabled
and we even check and yell when an interrupt handler
returns with interrupts enabled (see commit [b738a50a:
genirq: Warn when handler enables interrupts]).

So now this flag is a NOOP and can be removed.

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/drivers/serial-u16550.c

@@ -816,7 +816,7 @@ static int __devinit snd_uart16550_create(struct snd_card *card,
 
 	if (irq >= 0 && irq != SNDRV_AUTO_IRQ) {
 		if (request_irq(irq, snd_uart16550_interrupt,
-				IRQF_DISABLED, "Serial MIDI", uart)) {
+				0, "Serial MIDI", uart)) {
 			snd_printk(KERN_WARNING
 				   "irq %d busy. Using Polling.\n", irq);
 		} else {