qcacld-3.0: Use dma_iommu_mapping only ENABLE_SMMU_S1_TRANSLATION defined

In standard linux kernel, struct dma_iommu_mapping is not defined for
arm64, while in qualcomm linux kernel, struct dma_iommu_mapping is
defined for arm and arm64.

To fix build error in standard linux kernel, use struct dma_iommu_mapping
only when ENABLE_SMMU_S1_TRANSLATION is defined.

Change-Id: Ib02073163f2a38c47f864c6592fe2470046868ce
CRs-Fixed: 2496733

core/cds/src/cds_api.c

@@ -2880,7 +2880,6 @@ QDF_STATUS cds_smmu_mem_map_setup(qdf_device_t osdev, bool ipa_present)
 QDF_STATUS cds_smmu_mem_map_setup(qdf_device_t osdev, bool ipa_present)
 {
 	osdev->smmu_s1_enabled = false;
-	osdev->iommu_mapping = NULL;
 	return QDF_STATUS_SUCCESS;
 }
 #endif