net: dsa: hellcreek: Fix insertion of static FDB entries

The insertion of static FDB entries ignores the pass_blocked bit. That bit is
evaluated with regards to STP. Add the missing functionality.

Fixes: e4b27ebc ("net: dsa: Add DSA driver for Hirschmann Hellcreek switches")
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>