fix the GridGroup import

Author: jiel-nv

numba_cuda/numba/cuda/debuginfo.py

@@ -10,7 +10,7 @@
 from numba.cuda.core import config
 from numba.cuda import cgutils
 from numba.cuda.datamodel.models import ComplexModel, UnionModel, UniTupleModel
-from numba.cuda.ext_types import GridGroup
+from numba.cuda.types.ext_types import GridGroup
 from cuda.bindings import runtime