Revert "i40e: remove CONFIG_I40E_VXLAN"

This reverts commit 8fe269991aece394a7ed274f525d96c73f94109a.
The case where VXLAN is a module and i40e driver is inbuilt
will not be handled properly with this change since i40e
will have an undefined symbol vxlan_get_rx_port in it.

v2: Add a signed-off-by.

Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index 23b4580..bd6d9c0 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -281,7 +281,7 @@
 	u32 fd_atr_cnt;
 	u32 fd_tcp_rule;
 
-#if IS_ENABLED(CONFIG_VXLAN)
+#ifdef CONFIG_I40E_VXLAN
 	__be16  vxlan_ports[I40E_MAX_PF_UDP_OFFLOAD_PORTS];
 	u16 pending_vxlan_bitmap;
 
@@ -322,7 +322,9 @@
 #define I40E_FLAG_FD_ATR_ENABLED		BIT_ULL(22)
 #define I40E_FLAG_PTP				BIT_ULL(25)
 #define I40E_FLAG_MFP_ENABLED			BIT_ULL(26)
+#ifdef CONFIG_I40E_VXLAN
 #define I40E_FLAG_VXLAN_FILTER_SYNC		BIT_ULL(27)
+#endif
 #define I40E_FLAG_PORT_ID_VALID			BIT_ULL(28)
 #define I40E_FLAG_DCB_CAPABLE			BIT_ULL(29)
 #define I40E_FLAG_RSS_AQ_CAPABLE		BIT_ULL(31)