iommu: arm-smmu-impl: Convert to a generic reset implementation

Currently the QCOM specific smmu reset implementation is very
specific to SDM845 SoC and has a wait-for-safe logic which
may not be required for other SoCs. So move the SDM845 specific
logic to its specific reset function. Also add SC7180 SMMU
compatible for calling into QCOM specific implementation.

Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/d24a0278021bc0b2732636c5728efe55e7318a8b.1587407458.git.saiprakash.ranjan@codeaurora.org


Signed-off-by: Will Deacon <will@kernel.org>