ehea: fix allmulticast support

There was a bug in the mask of regtype parameter for registering a
multicast filter. It was ignoring the scope bit, which was wrongly being
used for all filters. The SCOPE_ALL value adds a filter that allows all
multicast packets and ignores the MAC parameter, just what allmulticast
needs. The normals filters, however, should not use SCOPE_ALL.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>