net: Add alloc_netdev_mqs function

Added alloc_netdev_mqs function which allows the number of transmit and
receive queues to be specified independenty.  alloc_netdev_mq was
changed to a macro to call the new function.  Also added
alloc_etherdev_mqs with same purpose.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>