ai: add missing gamma layer

aimodel/src/lib/ai/components/LayerConvNeXtGamma.py

@@ -0,0 +1,20 @@
+import tensorflow as tf
+
+# Code from https://github.com/leanderme/ConvNeXt-Tensorflow/blob/main/ConvNeXt.ipynb
+
+class LayerConvNeXtGamma(tf.keras.layers.Layer):
+    def __init__(self, const_val = 1e-6, dim = None, name=None, **kwargs):
+        super(LayerConvNeXtGamma, self).__init__(name=name)
+        
+        self.dim   = dim
+        self.const = const_val * tf.ones((self.dim))
+
+    def call(self, inputs, **kwargs):
+        return tf.multiply(inputs, self.const)
+    
+    def get_config(self):
+        config = super(LayerConvNeXtGamma, self).get_config()
+        
+        config.update({ "const": self.const, "dim": self.dim })
+        
+        return config