Fix TFDWConv() `c1 == c2` check (#7842)

models/tf.py

 
 class TFDWConv(keras.layers.Layer):
     # Depthwise convolution
-    def __init__(self, c1, c2, k=1, s=1, p=None, g=1, act=True, w=None):
+    def __init__(self, c1, c2, k=1, s=1, p=None, act=True, w=None):
         # ch_in, ch_out, weights, kernel, stride, padding, groups
         super().__init__()
-        assert g == c1 == c2, f'TFDWConv() groups={g} must equal input={c1} and output={c2} channels'
+        assert c1 == c2, f'TFDWConv() input={c1} must equal output={c2} channels'
         conv = keras.layers.DepthwiseConv2D(
             kernel_size=k,
             strides=s,