Help with patching PackageKit for *BSD

[Matthias Klumpp <matthias@tenstral.net>]

Hi!
I don't think this is the right place to request this help, but I
don't know a better one at time... (RFH seems to be too "big")
The problem is the following: PackageKit (Debian package
"src:packagekit") recently became Linux-specific by accident, and I
need someone who knows *BSD/portable-programming better than I do to
make it compile on *BSD again.
The problem is this code:
http://gitorious.org/packagekit/packagekit/blobs/master/lib/packagekit-glib2/pk-spawn-polkit-agent.c
On *BSD I get:
pk-spawn-polkit-agent.c:24:23: fatal error: sys/prctl.h: No such file
or directory
compilation terminated.
make[5]: *** [libpackagekit_glib2_la-pk-spawn-polkit-agent.lo] Error 1

But I don't know how to solve this otherwise. Hints and patches
welcome! this is really the only issue which blocks PK on kFreeBSD at
time.
Many thanks for any help!
Regards,
   Matthias