net: stmmac: dwmac4: Always update the MAC Hash Filter

We need to always update the MAC Hash Filter so that previous entries
are invalidated.

Found out while running stmmac selftests.

Fixes: b8ef7020

 ("net: stmmac: add support for hash table size 128/256 in dwmac4")
Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>