Revert "Change default current device to None (#39)" (#61)

This reverts commit e590884.

Author: PokhodenkoSA

dpctl/ocldrv.py

@@ -532,7 +532,7 @@ def __new__(cls):
             else:
                 _logger.warning("No GPU device")
 
-            cls._curr_device = None
+            cls._curr_device = DeviceEnv(cls._runtime[0][0].curr_env)
 
         return obj
 
@@ -555,10 +555,6 @@ def has_gpu_device(self):
 
         return Runtime._gpu_device is not None
 
-    def has_current_device(self):
-        ''' Returns True if GPU or CPU context manager is being used.'''
-
-        return Runtime._curr_device is not None
 
     def get_cpu_device(self):
         ''' Returns a cdata wrapper for the first available OpenCL
@@ -611,7 +607,6 @@ def dump(self):
 runtime = Runtime()
 has_cpu_device = runtime.has_cpu_device()
 has_gpu_device = runtime.has_gpu_device()
-has_current_device = runtime.has_current_device()
 
 #------- Global Functions