s390/mm: fix virtual-physical address confusion for swiotlb

swiotlb passes virtual addresses to set_memory_encrypted() and
set_memory_decrypted(), but uv_remove_shared() and uv_set_shared()
expect physical addresses. This currently works, because virtual
and physical addresses are the same.

Add virt_to_phys() to resolve the virtual-physical confusion.

Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Link: https://lore.kernel.org/r/20221107121221.156274-2-nrb@linux.ibm.com
Message-Id: <20221107121221.156274-2-nrb@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>