Merge branch 'docs-22392-add-missing-eks-permission' into 'master'

Add missing IAM permission to EKS cluster docs

See merge request gitlab-org/gitlab!20821

doc/user/project/clusters/add_remove_clusters.md

@@ -300,6 +300,7 @@ new Kubernetes cluster to your project:
                       "iam:AttachRolePolicy",
                       "iam:CreateRole",
                       "iam:CreateInstanceProfile",
+                      "iam:CreateServiceLinkedRole",
                       "iam:GetRole",
                       "iam:ListRoles",
                       "iam:PassRole",