enic: provision for multiple Rx/Tx queues; prepare for RSS support

Provision for multiple Rx/Tx queues.  Max of 8 WQs and 8 RQs.  Max for
completion queue is 8+8=16 and max for interrupt resources is 8+8+2.

Add driver/firmware interface for setting up RSS secret key and indirection
table.

Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>