forgot to change the conftest to pytest_plugin

Author: farshidsp

tests/python/contrib/test_hexagon/test_run_unit_tests.py

@@ -19,7 +19,7 @@
 import pytest
 import numpy as np
 from tvm.contrib.hexagon.build import HexagonLauncher
-from .conftest import requires_hexagon_toolchain
+from tvm.contrib.hexagon.pytest_plugin import requires_hexagon_toolchain
 
 
 # use pytest -sv to observe gtest output