iommu/arm-smmu-qcom: Add an adreno-smmu-priv callback to get pagefault info

Add a callback in adreno-smmu-priv to read interesting SMMU
registers to provide an opportunity for a richer debug experience
in the GPU driver.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210610214431.539029-3-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>