[MoE Refactor][Test] FusedMoE layer test (#24675)

Signed-off-by: Bill Nell <bnell@redhat.com>
Co-authored-by: Robert Shaw <114415538+robertgshaw2-redhat@users.noreply.github.com>

tests/kernels/moe/conftest.py

@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import pytest
+
+
+def pytest_addoption(parser):
+    parser.addoption(
+        "--subtests", action="store", type=str, default=None, help="subtest ids"
+    )
+
+
+@pytest.fixture
+def subtests(request):
+    return request.config.getoption("--subtests")