i40e/i40evf: create and use new unified header file

This moves a header for i40evf to include/linux/avf/virtchnl.h.
The directory name AVF is an acronym for the Intel(R) Adaptive
Virtual Function.

This first step creates the new file, which is a rename of
drivers/net/ethernet/intel/i40evf/i40e_virtchnl.h to
include/linux/avf/virtchnl.h, and should show up in git
as a rename when using git log --follow.

To keep things building after the move, the changes to the i40evf
driver are made to point to the new include file location.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

MAINTAINERS

@@ -6738,6 +6738,7 @@ F:	Documentation/networking/i40e.txt
 F:	Documentation/networking/i40evf.txt
 F:	drivers/net/ethernet/intel/
 F:	drivers/net/ethernet/intel/*/
+F:	include/linux/avf/virtchnl.h
 
 INTEL RDMA RNIC DRIVER
 M:     Faisal Latif <faisal.latif@intel.com>

drivers/net/ethernet/intel/i40evf/i40e_common.c

@@ -27,7 +27,7 @@
 #include "i40e_type.h"
 #include "i40e_adminq.h"
 #include "i40e_prototype.h"
-#include "i40e_virtchnl.h"
+#include <linux/avf/virtchnl.h>
 
 /**
  * i40e_set_mac_type - Sets MAC type

drivers/net/ethernet/intel/i40evf/i40e_prototype.h

@@ -29,7 +29,7 @@
 
 #include "i40e_type.h"
 #include "i40e_alloc.h"
-#include "i40e_virtchnl.h"
+#include <linux/avf/virtchnl.h>
 
 /* Prototypes for shared code functions that are not in
  * the standard function pointer structures.  These are

drivers/net/ethernet/intel/i40evf/i40evf.h

@@ -43,7 +43,7 @@
 #include <net/udp.h>
 
 #include "i40e_type.h"
-#include "i40e_virtchnl.h"
+#include <linux/avf/virtchnl.h>
 #include "i40e_txrx.h"
 
 #define DEFAULT_DEBUG_LEVEL_SHIFT 3