For now it always returns '0' (false), but once the iommu work is in
place to enable per-process pagetables we can update the value returned.

Userspace needs to know this to make an informed decision about exposing
KHR_robustness.
Signed-off-by: NRob Clark <robdclark@chromium.org>
Reviewed-by: NJordan Crouse <jcrouse@codeaurora.org>