oprofile: Implement Intel architectural perfmon

This patchkit implements architectural perfmon support in oprofile.
This allows to do generic profiling of a few standard events in all 
newer Intel CPUs, including Atom and Nehalem. The CPU describes
its event in CPUID so they can be used without knowing anything
about the CPU.

The code requires some changes to the oprofile userland, which
I am posting separately to the oprofile list.

-Andi