[UT] Generalize Proton tests by providing device fixture (triton-lang#9351)

The same approach as with other unit tests.

---------

Signed-off-by: Anatoly Myachev <anatoly.myachev@intel.com>
Co-authored-by: Keren Zhou <kerenzhou@openai.com>

Author: anmyachev

third_party/proton/test/conftest.py

@@ -1,6 +1,15 @@
 import pytest
 
 
+def pytest_addoption(parser):
+    parser.addoption("--device", action="store", default="cuda")
+
+
+@pytest.fixture
+def device(request):
+    return request.config.getoption("--device")
+
+
 @pytest.fixture
 def fresh_knobs():
     from triton._internal_testing import _fresh_knobs_impl