gitignore: add tags file to .gitignore

This file can be generated by ctags and should not show in git status.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
iz-phy: fix del interface

This patch fix the del_phy_response_event and change
IEEE802154_ADD_IFACE to IEEE802154_DEL_IFACE otherwise we run into
deadlock in calling of iz del.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>