selftests: KVM: Add fpu and one reg set/get library functions

Add library access to more registers.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/20200131100205.74720-5-frankja@linux.ibm.com


Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>