net: dsa: mv88e6xxx: Fix name of switch 88E6141

The switch name is emitted in the kernel log, so having the right name
there is nice.

Fixes: 1558727a ("net: dsa: mv88e6xxx: Add support for ethernet switch 88E6141")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>