KVM: s390: split kvm_s390_logical_to_effective

Split kvm_s390_logical_to_effective to a generic function called
_kvm_s390_logical_to_effective. The new function takes a PSW and an address
and returns the address with the appropriate bits masked off. The old
function now calls the new function with the appropriate PSW from the vCPU.

This is needed to avoid code duplication for vSIE.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: stable@vger.kernel.org # for VSIE: correctly handle MVPG when in VSIE
Link: https://lore.kernel.org/r/20210302174443.514363-2-imbrenda@linux.ibm.com


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