bnx2x: Support ndo_set_rxmode in VF driver

The VF driver uses the 'q_filter' request in the VF <-> PF channel to
have the PF configure the requested rxmode to device. ndo_set_rxmode
is called under bottom half lock, so sleeping until the response
arrives over the VF <-> PF channel is out of the question. For this reason
the VF driver returns from the ndo after scheduling a work item, which
in turn processes the rx mode request and adds the classification
information through the VF <-> PF channel accordingly.

Signed-off-by: Ariel Elior <ariele@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>