ALSA: AT73C213: Rectify misleading comment.

The Atmel SSC can divide by even numbers, not only powers of two.
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/spi/at73c213.c

@@ -155,7 +155,7 @@ static int snd_at73c213_set_bitrate(struct snd_at73c213 *chip)
 	if (max_tries < 1)
 		max_tries = 1;
 
-	/* ssc_div must be a power of 2. */
+	/* ssc_div must be even. */
 	ssc_div = (ssc_div + 1) & ~1UL;
 
 	if ((ssc_rate / (ssc_div * 2 * 16)) < BITRATE_MIN) {