[PATCH] igb: add IGB_DCA instead of selecting INTEL_IOATDMA

[Jeff Garzik]

Jeff Kirsher wrote:
> Add a bool IGB_DCA defined to y if IGB and DCA are enabled, but IGB isn't y while DCA=m.  And thus remove the need to select INTEL_IOATDMA when IGB is enabled, so that non-x86 architectures can build the igb driver.
> Based on work/patch from Brice Goglin <brice at myri.com>
> 
> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher at intel.com>

applied