Revert "net/mlx5: Kconfig: Fix MLX5_EN/VXLAN build issue"

This reverts commit 69976fb1.

We cannot select VXLAN when IPv4 support is disabled, that just gives
us additional build errors, including:

warning: (MLX5_CORE_EN) selects VXLAN which has unmet direct dependencies (NETDEVICES && NET_CORE && INET)
In file included from ../drivers/net/vxlan.c:36:0:
include/net/udp_tunnel.h: In function 'udp_tunnel_handle_offloads':
include/net/udp_tunnel.h:112:9: error: implicit declaration of function 'iptunnel_handle_offloads' [-Werror=implicit-function-declaration]
  return iptunnel_handle_offloads(skb, type);
         ^~~~~~~~~~~~~~~~~~~~~~~~

I'm sending a proper fix for the original bug in a separate patch.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx5/core/Kconfig

@@ -14,7 +14,6 @@ config MLX5_CORE_EN
 	bool "Mellanox Technologies ConnectX-4 Ethernet support"
 	depends on NETDEVICES && ETHERNET && PCI && MLX5_CORE
 	select PTP_1588_CLOCK
-	select VXLAN if MLX5_CORE=y
 	default n
 	---help---
 	  Ethernet support in Mellanox Technologies ConnectX-4 NIC.