FIX: NetBSD/cobalt now compiles 7.2.1

Hi all,

I've been messing with NetBSD/cobalt 1.5.3, and have found that the template
file for NetBSD could be improved a little - without the following change
the system dies in s_lock.c because the opcodes are only available with the
-mips2 flag, and it's not correctly picked up for this platform.

The file src/template/netbsd should have three lines added (similar to the
current src/template/linux one), so the full file looks like this:

----
CFLAGS=-O2

case $host_cpu in
cobalt*) CFLAGS="$CFLAGS -mips2";;
esac
----

With this change made the standard 7.2.1 tarball compiled without a single
problem. I've yet to test speed and stability.

--
Ian Spray