s390/oprofile: move hwsampler interfaces to cpu_mf.h

Extract and move the oprofile hwsampler data structures and interfaces to
the cpu_mf.h header file which contains common interface definitions
for the various CPU-measurement facilities.   This change is necessary for
a new perf PMU.

Few interface names have been revised to fit to the latest CPU-measurement
facilities documentation.  Also declare the data structures as __packed and
correct checkpatch findings.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>