drm/msm: Fix display fault handling

drm/msm: Fix display fault handling

It turns out that when the display is enabled by the bootloader, we can
get some transient iommu faults from the display.  Which doesn't go over
too well when we install a fault handler that is gpu specific.  To avoid
this, defer installing the fault handler until we get around to setting
up per-process pgtables (which is adreno_smmu specific).  The arm-smmu
fallback error reporting is sufficient for reporting display related
faults (and in fact was all we had prior to f8f934c180f629bb927a04fd90d)

Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reported-by: Yassine Oudjana <y.oudjana@protonmail.com>
Fixes: 2a574cc05d38 ("drm/msm: Improve the a6xx page fault handler")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Tested-by: Yassine Oudjana <y.oudjana@protonmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210707180113.840741-1-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>