s390/ap: rework assembler functions to use unions for in/out register variables

The inline assembler functions ap_aqic() and ap_qact() used two
variables declared on the very same register. One variable was for
input only, the other for output. Looks like newer versions of the gcc
don't like this. Anyway it is a better coding to use one variable
(which may have a union data type) on one register for input and
output. So this patch introduces unions and uses only one variable now
for input and output for GR1 for the PQAP(QACT) and PQAP(QIC)
invocation.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>