net: dsa: tag_gswip: fix typo in tagger name

The correct name is GSWIP (Gigabit Switch IP). Typo was introduced in
875138f8 ("dsa: Move tagger name into its ops structure") while
moving tagger names to their structures.

Fixes: 875138f8

 ("dsa: Move tagger name into its ops structure")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Alexander Lobakin <alobakin@dlink.ru>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: David S. Miller <davem@davemloft.net>