net: bcmgenet: remove priv->int0_mask and priv->int1_mask

Remove unused priv->int0_mask and priv->int1_mask.

Signed-off-by: Petri Gynther <pgynther@google.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>