net: dsa: mv88e6xxx: fix 88E6321 family comment

MV88E6XXX_FAMILY_6321 is undefined, 88E6321's family is 88E6320,
fix this.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -2959,7 +2959,7 @@ static const struct mv88e6xxx_ops mv88e6320_ops = {
 };
 
 static const struct mv88e6xxx_ops mv88e6321_ops = {
-	/* MV88E6XXX_FAMILY_6321 */
+	/* MV88E6XXX_FAMILY_6320 */
 	.irl_init_all = mv88e6352_g2_irl_init_all,
 	.get_eeprom = mv88e6xxx_g2_get_eeprom16,
 	.set_eeprom = mv88e6xxx_g2_set_eeprom16,