ixgbe: Default to 1 pool always being allocated

We might as well configure the limit to default to 1 pool always for the
interface. This accounts for the fact that the PF counts as 1 pool if
SR-IOV is enabled, and in general we are always running in 1 pool mode when
RSS or DCB is enabled as well, though we don't need to actually evaluate
any of the VMDq features in those cases.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>