iommu/arm-smmu: Don't use VMIDs for stage-1 translations

Although permitted by the architecture, using VMIDs for stage-1
translations causes a complete nightmare for hypervisors, who end up
having to virtualise the VMID space across VMs, which may be using
multiple VMIDs each.

To make life easier for hypervisors (which might just decide not to
support this VMID virtualisation), this patch reworks the stage-1
context-bank TLB invalidation so that:

	- Stage-1 mappings are marked non-global in the ptes
	- Each Stage-1 context-bank is assigned an ASID in TTBR0
	- VMID 0 is reserved for Stage-1 context-banks

This allows the hypervisor to overwrite the Stage-1 VMID in the CBAR
when trapping the write from the guest.

Change-Id: I355e99da8d28b4706d909314a7562b2a03da78a5
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Git-commit: 1463fe44fd0f87af0404e2c147ab9724081b7235
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>