hw/arm/smmuv3: Cache/invalidate config data

Let's cache config data to avoid fetching and parsing STE/CD
structures on each translation. We invalidate them on data structure
invalidation commands.

We put in place a per-smmu mutex to protect the config cache. This
will be useful too to protect the IOTLB cache. The caches can be
accessed without BQL, ie. in IO dataplane. The same kind of mutex was
put in place in the intel viommu.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1529653501-15358-3-git-send-email-eric.auger@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>