s390/cpu_mf: add store cpu counter multiple instruction support

Add support for the STORE CPU COUNTER MULTIPLE instruction to extract
a range of counters from a counter set.

An assembler macro is used to create the instruction opcode because
the counter set identifier is part of the instruction and, thus,
cannot be easily specified as parameter.

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