mpls: load mpls_gso after mpls_iptunnel

mpls_iptunnel is used only for mpls encapsuation, and if encaplusated
packet is larger than MTU we need mpls_gso for segmentation.
Signed-off-by: Alexander Ovechkin <ovov@yandex-team.ru>
Acked-by: Dmitry Yakunin <zeil@yandex-team.ru>
Reviewed-by: David Ahern <dsahern@gmail.com>
Link: https://lore.kernel.org/r/20201020114333.26866-1-ovov@yandex-team.ruSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/mpls/mpls_iptunnel.c

@@ -300,5 +300,6 @@ static void __exit mpls_iptunnel_exit(void)
 module_exit(mpls_iptunnel_exit);
 
 MODULE_ALIAS_RTNL_LWT(MPLS);
+MODULE_SOFTDEP("post: mpls_gso");
 MODULE_DESCRIPTION("MultiProtocol Label Switching IP Tunnels");
 MODULE_LICENSE("GPL v2");