Documentation: networking: dsa: Update tagging protocols

Add Qualcomm QCA tagging introduced in cafdc45c9 to the
list of supported protocols.

Signed-off-by: Fabian Mewes <architekt@coding4coffee.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/dsa/dsa.txt

@@ -67,13 +67,14 @@ Note that DSA does not currently create network interfaces for the "cpu" and
 Switch tagging protocols
 ------------------------
 
-DSA currently supports 4 different tagging protocols, and a tag-less mode as
+DSA currently supports 5 different tagging protocols, and a tag-less mode as
 well. The different protocols are implemented in:
 
 net/dsa/tag_trailer.c: Marvell's 4 trailer tag mode (legacy)
 net/dsa/tag_dsa.c: Marvell's original DSA tag
 net/dsa/tag_edsa.c: Marvell's enhanced DSA tag
 net/dsa/tag_brcm.c: Broadcom's 4 bytes tag
+net/dsa/tag_qca.c: Qualcomm's 2 bytes tag
 
 The exact format of the tag protocol is vendor specific, but in general, they
 all contain something which: