[TOPI] Update conv schedule on rasp (#497)

Author: ZihengJiang

topi/python/topi/nn/__init__.py

@@ -4,7 +4,7 @@
 
 from .batch_norm import *
 from .conv2d import *
-from .depthwise_convolution import *
+from .depthwise_conv2d import *
 from .elemwise import *
 from .dilate import *
 from .flatten import *

topi/python/topi/nn/depthwise_convolution.py renamed to topi/python/topi/nn/depthwise_conv2d.py

@@ -32,8 +32,8 @@
     SpatialPack(1, 4, 8, 4, 8, False),
     SpatialPack(2, 2, 8, 1, 4, False),
     SpatialPack(2, 2, 8, 1, 8, False),
-    SpatialPack(1, 1, 16, 1, 4, False),
-    SpatialPack(1, 1, 4, 1, 4, True),
+    Im2ColPack(7, 4, 1, 16, False),
+    Im2ColPack(7, 4, 1, 4, True),
 ]
 
 def _schedule_conv2d(wkl):