lantiq: xrx200: autoload lantiq_gswip and tag_gswip to fix failsafe mode

lantiq: xrx200: autoload lantiq_gswip and tag_gswip to fix failsafe mode

lantiq_gswip and tag_gswip were not loaded during failsafe, leaving the
switch uninitialised. This caused LAN1 port to show no link, making
SSH-based recovery impossible.
Add the autoload flag and include tag_gswip (which was also missing from
the autoload list) so the switch initialises correctly in failsafe mode.

Tested on BT HomeHub 5A (lantiq/xrx200).

Fixes: https://github.com/openwrt/openwrt/issues/22480
Signed-off-by: Benjamin Levine <benjaminmileslevine@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/22514
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>