CMSIS-NN: Add dilation support for conv (#1377)

* Adds dilation support for convolution implementation.
* Adds corresponding unit tests for dilation.
* Fixes generate script bug that it was always regenerating
   data.
* DSP and scalar implementation are partly combined so scalar
   implementation now also uses im2col buffer.

Change-Id: If6c57594b5122827597529ab628586135ec975fe
Co-authored-by: Patrik Laurell
diff --git a/ARM.CMSIS.pdsc b/ARM.CMSIS.pdsc
index 9267266..6d58fea 100644
--- a/ARM.CMSIS.pdsc
+++ b/ARM.CMSIS.pdsc
@@ -14,6 +14,7 @@
       CMSIS-NN: 3.1.0 (see revision history for details)
        - Support for int16 convolution and fully connected for reference implementation
        - Support for DSP extension optimization for int16 convolution and fully connected
+       - Support for dilation for int8 convolution
     </release>
     <release version="5.8.0" date="2021-06-24">
       CMSIS-Core(M): 5.5.0 (see revision history for details)