arm64: dts: stratix10: fix multicast filtering

On Stratix 10, the EMAC has 256 hash buckets for multicast filtering. This
needs to be specified in DTS, otherwise the stmmac driver defaults to 64
buckets and initializes the filter incorrectly. As a result, e.g. valid
IPv6 multicast traffic ends up being dropped.

Fixes: 78cd6a9d

 ("arm64: dts: Add base stratix 10 dtsi")
Cc: stable@vger.kernel.org
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>