xen/arm : smmuv3: Fix to handle multiple StreamIds per device.

xen/arm : smmuv3: Fix to handle multiple StreamIds per device.

SMMUv3 driver does not handle multiple StreamId if the master device
supports more than one StreamID.

This bug was introduced when the driver was ported from Linux to XEN.
dt_device_set_protected(..) should be called from add_device(..) not
from the dt_xlate(..).

Move dt_device_set_protected(..) from dt_xlate(..) to add_device().

Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>