Update encoder.py

Author: fishmarch

projects/mmdet3d_plugin/bevformer/modules/encoder.py

@@ -146,7 +146,7 @@ def point_sampling(self, reference_points, pc_range,  img_metas):
 
         return reference_points_cam, bev_mask
 
-    # @auto_fp16() # This may cause 'grad_norm: nan'
+    @auto_fp16() # This may cause 'grad_norm: nan'
     def forward(self,
                 bev_query,
                 key,