ixgbe: Merge all FCoE percpu values into a single structure

This change merges the 2 statistics values for noddp and noddp_ext_buff
and the dma_pool into a single structure that can be allocated per CPU.

The advantages to this are several fold.  First we only need to do one
alloc_percpu call now instead of 3, so that means less overhead for
handling memory allocation failures.  Secondly in the case of
ixgbe_fcoe_ddp_setup we only need to call get_cpu once which makes things a
bit cleaner since we can drop a put_cpu() from the exception path.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>