iommu/arm-smmu: Support client configured dynamic domains only in QGKI

Dynamic domains cannot be completely supported using a kernel that does
not allow a device to attach to several domains. So, introduce
CONFIG_IOMMU_DYNAMIC_DOMAINS, which will only be set when there is
confidence that the kernel supports dynamic domains.

Change-Id: I37a6fd933c695d17b25a501b3e1e807e270c29ee
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>