iommu/arm-smmu-v3: Use pci_ats_supported()

The new pci_ats_supported() function checks if a device supports ATS and
is allowed to use it.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200520152201.3309416-4-jean-philippe@linaro.org


Signed-off-by: Joerg Roedel <jroedel@suse.de>