[S390] spp: fix compilation for CONFIG_32BIT

Fix build breakage for CONFIG_32BIT caused by cd3b70f5
"[S390] virtualization aware cpu measurement"

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>