xen/arm: smmuv1: Consolidate stream map entry state

xen/arm: smmuv1: Consolidate stream map entry state

Backport commit 1f3d5ca43019bff1105838712d55be087d93c0da
"iommu/arm-smmu: Consolidate stream map entry state" from the Linux
kernel.

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: Consolidate stream map entry state

    In order to consider SMR masking, we really want to be able to validate
    ID/mask pairs against existing SMR contents to prevent stream match
    conflicts, which at best would cause transactions to fault unexpectedly,
    and at worst lead to silent unpredictable behaviour. With our SMMU
    instance data holding only an allocator bitmap, and the SMR values
    themselves scattered across master configs hanging off devices which we
    may have no way of finding, there's essentially no way short of digging
    everything back out of the hardware. Similarly, the thought of power
    management ops to support suspend/resume faces the exact same problem.

    By massaging the software state into a closer shape to the underlying
    hardware, everything comes together quite nicely; the allocator and the
    high-level view of the data become a single centralised state which we
    can easily keep track of, and to which any updates can be validated in
    full before being synchronised to the hardware itself.

    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>