Restoring USE_NV_BINDING so we don't customer code.

Author: rparolin

numba_cuda/numba/cuda/cudadrv/driver.py

@@ -62,6 +62,10 @@
     ObjectCode,
 )
 
+# For backwards compatibility: indicate that the NVIDIA CUDA Python bindings are
+# in use. Older code checks this flag to branch on binding-specific behavior.
+USE_NV_BINDING = True
+
 # There is no definition of the default stream in the Nvidia bindings (nor
 # is there at the C/C++ level), so we define it here so we don't need to
 # use a magic number 0 in places where we want the default stream.