[CMake] cmake under OpenBSD: rpath support misconfigured

[Frank Mertens]

I started using cmake (2.6.3) under OpenBSD (4.5) and found it unwillingly to link my software correctly.
The issue had been described some time ago: http://www.cmake.org/pipermail/cmake/2006-November/011851.html.
I figured out that cmake-2.6.3/Modules/Platform/NetBSD.cmake contains some meaningful (and functional!)
configuration while OpenBSD.cmake is empty.
The solution was simple: cp NetBSD.cmake OpenBSD.cmake.
I think those two files can be kept safely identical.

Thx in advance,
Frank.