net: dsa: mv88e6xxx: use correct .stats_set_histogram() on Topaz

Commit 40cff8fc

 ("net: dsa: mv88e6xxx: Fix stats histogram mode")
introduced wrong .stats_set_histogram() method for Topaz family.

The Peridot method should be used instead.

Signed-off-by: Marek Behún <kabel@kernel.org>
Fixes: 40cff8fc

 ("net: dsa: mv88e6xxx: Fix stats histogram mode")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>