ixgbe: Make descriptor ring allocations NUMA-aware

This patch allocates the ring structures themselves on each
NUMA node along with the buffer_info structures.  This way we
don't allocate the entire ring memory on a single node in one
big block, thus reducing NUMA node memory crosstalk.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>