[mlir] Update BUILD.bazel to include scf_tests

Author: Mogball

utils/bazel/llvm-project-overlay/mlir/unittests/BUILD.bazel

@@ -104,6 +104,21 @@ cc_test(
     ],
 )
 
+cc_test(
+    name = "scf_tests",
+    size = "small",
+    srcs = glob([
+        "Dialect/SCF/*.cpp",
+        "Dialect/SCF/*.h",
+    ]),
+    deps = [
+        "//llvm:gtest_main",
+        "//mlir:Parser",
+        "//mlir:SCFDialect",
+        "//mlir:StandardOps",
+    ],
+)
+
 cc_test(
     name = "sparse_tensor_tests",
     size = "small",