netifd: @aliases use layer 3 devices instead of main devices
Fixes dhcpv6 protocol alias

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@35187 3c298f89-4303-0410-b956-a3cf2f4a3e73
ppp: don't automatically set IPv6 default route
* Fixes "ndisc_router_discovery() failed to add default route"

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@35188 3c298f89-4303-0410-b956-a3cf2f4a3e73
odhcp6c: Detect a different MAC if interface has none
* Fixes DHCPv6 behaviour over PPP and similar

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@35189 3c298f89-4303-0410-b956-a3cf2f4a3e73