iommu/arm-smmu-qcom: Add generic qcom,smmu-500 match entry

iommu/arm-smmu-qcom: Add generic qcom,smmu-500 match entry

Add generic qcom,smmu-500 compatibility string. Newer platforms should
use this generic entry rather than declaring per-SoC entries.

Reviewed-by: Sai Prakash Ranjan <quic_saipraka@quicinc.com>
Tested-by: Sai Prakash Ranjan <quic_saipraka@quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20221114170635.1406534-11-dmitry.baryshkov@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>