Rename smmu node to iommu to fix dtbs_check warning:
 k3-j721e-common-proc-board.dt.yaml: smmu@36600000: $nodename:0: 'smmu@36600000' does not match '^iommu@[0-9a-f]*'
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NTero Kristo <t-kristo@ti.com>