cpusets: provide another web page URL in MAINTAINERS file

Add URL for another CPUSETS web page to the MAINTAINERS file.

This URL provides links to major LGPL user level C libraries supporting
cpuset usage and user level cpu and node masks.

Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>