KVM: s390: allow sie enablement for multi-threaded programs

Improve the code to upgrade the standard 2K page tables to 4K page tables
with PGSTEs to allow the operation to happen when the program is already
multi-threaded.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --cc arch/s390/include/asm/mmu.h
Simple merge

diff --cc arch/s390/include/asm/mmu_context.h
Simple merge

diff --cc arch/s390/include/asm/pgtable.h
Simple merge

diff --cc arch/s390/mm/pgtable.c
Simple merge