NETLINK is going to replace rtsock and a number of other ioctl/sysctl interfaces.
In-base utilies such as route(8), netstat(8) and soon ifconfig(8)
are being converted to use netlink sockets as a transport between
kernel and userland.
In the current configuration, it still possible have the kernel
without NETLINK (`nooptions NETLINK`) and use the aforementioned
utilies by buidling the world with `WITHOUT_NETLINK` src.conf knob.
However, this approach does not cover the cases when person unintentionally
builds a custom kernel without netlink and tries to use the standard userland.
This change adds `option NETLINK` to the default options for each
architecture, fixing the custom kernel issue.
For arm, this change uses `std.armv6` and `std.armv7` (netlink already in)
instead of DEFAULTS.
Reviewed By: imp
Differential Revision: https://reviews.freebsd.org/D39339
3091d980f5