sprs in ubunut_kvm_unit_tests timeout on PowerPC

[Po-Hsu Lin]

Issue found on:
  * F 5.13.0-23.23~20.04.2 node entei
  * H 5.11.0-44.48 node entei
  * J 5.15.0-14.14 node baltar

With the kvm-unit-tests repo updated to head SHA1 745f5eb8 ("runtime: Use find_word with groups")
The sprs test no longer failing with LP: #1943845 sprs - SPR 9: 000000000000000000 <==> 0xc0000000001222bc
but timeout instead

 Running 'kvm-ok'
 INFO: /dev/kvm exists
 KVM acceleration can be used
'ppc64_cpu --smt=off'
'/home/ubuntu/autotest/client/tmp/ubuntu_kvm_unit_tests/src/kvm-unit-tests/tests/sprs'
 BUILD_HEAD=8a30588c
 timeout -k 1s --foreground 90s /usr/bin/qemu-system-ppc64 -nodefaults -machine pseries,accel=kvm -bios /tmp/tmp.WcxYfc7M2a -display none -serial stdio -kernel /tmp/tmp.lWY2f2ZlCx -smp 1 -append -w # -initrd /tmp/tmp.6xXZ6LhKkL
 Settings SPRs to 0xcafefacec0debabe...
 Now migrate the VM, then press a key to continue...
 qemu-system-ppc64: terminating on signal 15 from pid 15314 (timeout)
 FAIL sprs (timeout; duration=90s)

[Luke Nowakowski-Krijger (lukenow)]

Found on 2022.01.31/bionic/linux/4.15.0-169.177 on instance dryden

[Po-Hsu Lin (cypressyew)]

This issue has gone with update.