[][openwrt][mt7988][crypto][Fix compile error without hnat]

[Description]
Fix compile error without hnat.
This patch modify the tdma value in ethernet driver to forward IPsec
packets to EIP197. If hnat module is not enabled, skb_hnat_cdrt() and
is_magic_tag_valid() will lead to compile error. Include these code into
compile if defined.

[Release-log]
N/A


Change-Id: I11256a0c836e00407d6737db1ac95d003d8b5093
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/8250362
1 file changed