simple standalone reference pebs driver

PEBS "Precise Event Based Sampling" is a profiling technology in Intel CPUs,
that uses microcode to do (mostly) precise event samples.

The driver is "free running" and minimizes interrupts, to allow a maximum 
PEBS frequency. Interrupts are only triggered when the PEBS buffer is full.

This will take over the PEBS hardware from perf and may cause conflicts.

To build user tools use "make user"

sample file format:
{8 bytes 	ip}


simple-pebs.c	Linux simple pebs driver
dumper.c	Dump samples running from running Linux driver. -b to write binary sample file
samples.c	Decode (ELF symbols) sample from running Linux driver.

gencsv.c 	Generate Vtune style CSV format from sample file (not useful)
histogram.c	Generate histogram from sample file

toperf.c	Generate perf.data from sample file