net: dsa: mv88e6xxx: Don't support >1G speeds on 6191X on ports other than 10

Model 88E6191X only supports >1G speeds on port 10. Port 0 and 9 are
only 1G.

Fixes: de776d0d ("net: dsa: mv88e6xxx: add support for mv88e6393x family")
Signed-off-by: Marek Behún <kabel@kernel.org>
Cc: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20211104171747.10509-1-kabel@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>