net: dsa: tag_8021q: remove old comment regarding dsa_8021q_netdev_ops

Since commit 129bd7ca ("net: dsa: Prevent usage of NET_DSA_TAG_8021Q
as tagging protocol"), dsa_8021q_netdev_ops no longer exists, so remove
the comment that talks about it.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20220818143808.2808393-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/dsa/tag_8021q.c

@@ -2,9 +2,7 @@
 /* Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com>
  *
  * This module is not a complete tagger implementation. It only provides
- * primitives for taggers that rely on 802.1Q VLAN tags to use. The
- * dsa_8021q_netdev_ops is registered for API compliance and not used
- * directly by callers.
+ * primitives for taggers that rely on 802.1Q VLAN tags to use.
  */
 #include <linux/if_vlan.h>
 #include <linux/dsa/8021q.h>