xen/arm: smmuv1: Handle stream IDs more dynamically

xen/arm: smmuv1: Handle stream IDs more dynamically

Backport commit 21174240e4f4439bb8ed6c116cdbdc03eba2126e
"iommu/arm-smmu: Handle stream IDs more dynamically" from the Linux
ernel.

This patch is the preparatory work to fix the stream match conflict
when two devices have the same stream-id.

Original commit message:
    iommu/arm-smmu: Handle stream IDs more dynamically

    Rather than assuming fixed worst-case values for stream IDs and SMR
    masks, keep track of whatever implemented bits the hardware actually
    reports. This also obviates the slightly questionable validation of SMR
    fields in isolation - rather than aborting the whole SMMU probe for a
    hardware configuration which is still architecturally valid, we can
    simply refuse masters later if they try to claim an unrepresentable ID
    or mask (which almost certainly implies a DT error anyway).

    Acked-by: Will Deacon <will.deacon@arm.com>
    Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
    Signed-off-by: Robin Murphy <robin.murphy@arm.com>
    Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>