sound: oss: au1550_ac97: simplify au1550_delay()

au1550_delay() uses loop with schedule_timeout() to unconditionally wait
for msec. Use schedule_timeout_uninteruptible() instead.

Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>