iommu: arm-smmu: Disable default DMA Domain support

The current upstream arm-smmu implementation supports a 'stub' default DMA
domain. This domain is automatically attached at bootup, but has no context
bank or stream-ids. A device may choose to attach a different domain with
other context bank/stream-id settings. When the device detaches from this
domain, the 'default domain' is again attached automatically. This behavior
conflicts with several qcom-added features.

Dynamic domains:

When a dynamic domain is detached, the stream-ids of the dynamic domain
must not be removed.

Power:

Qcom uses the attach_dev() and detach_dev() callbacks as a signal that
power to the iommu can be removed. But with a default domain, the iommu is
always attached.

Change-Id: I84ec42667b986e5abfdbb0b5b7956a38532cabaa
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>