be2net: refactor be_set_rx_mode() and be_vid_config() for readability

This patch re-factors the filter setting (uc-list, mc-list, promisc, vlan)
code in be_set_rx_mode() and be_vid_config() to make it more readable
and reduce code duplication.
This patch adds a separate field to track the state/mode of filtering,
along with moving all the filtering related fields to one place in be
be_adapter structure.

Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>