sound: Address some XXX comments regarding AC'97 IDs

These seem harmless to address. Not sure why the original author did not
just assign the appropriate names if he knew they were wrong.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D56044

sys/dev/sound/pcm/ac97.c

@@ -125,12 +125,7 @@ static const struct ac97_vendorid ac97vendorid[] = {
 	{ 0x57454300, "Winbond" },
 	{ 0x574d4c00, "Wolfson" },
 	{ 0x594d4800, "Yamaha" },
-	/* 
-	 * XXX This is a fluke, really! The real vendor
-	 * should be SigmaTel, not this! This should be
-	 * removed someday!
-	 */
-	{ 0x01408300, "Creative" },
+	{ 0x01408300, "SigmaTel" },
 	{ 0x00000000, NULL }
 };
 
@@ -238,12 +233,7 @@ static struct ac97_codecid ac97codecid[] = {
 	{ 0x594d4800, 0x00, 0, "YMF743",	0 },
 	{ 0x594d4802, 0x00, 0, "YMF752",	0 },
 	{ 0x594d4803, 0x00, 0, "YMF753",	0 },
-	/* 
-	 * XXX This is a fluke, really! The real codec
-	 * should be STAC9704, not this! This should be
-	 * removed someday!
-	 */
-	{ 0x01408384, 0x00, 0, "EV1938",	0 },
+	{ 0x01408384, 0x00, 0, "STAC9704",	0 },
 	{ 0, 0, 0, NULL, 0 }
 };