CMSIS-NN: Add int16 support for depthwise_conv (#1406)

Adds new function arm_depthwise_conv_s16 including dilation support and
corresponding unit tests.

Change-Id: Ia393679990fdcb94edd062c53b76346c67e3405b
diff --git a/ARM.CMSIS.pdsc b/ARM.CMSIS.pdsc
index b6692de..0938273 100644
--- a/ARM.CMSIS.pdsc
+++ b/ARM.CMSIS.pdsc
@@ -16,6 +16,7 @@
        - Support for DSP extension optimization for int16 convolution and fully connected
        - Support dilation for int8 convolution
        - Support dilation for int8 depthwise convolution
+       - Support for int16 depthwise conv for reference implementation including dilation
       CMSIS-RTOS2:
         - RTX 5.5.4 (see revision history for details)
     </release>
@@ -2820,6 +2821,7 @@
         <file category="source" name="CMSIS/NN/Source/ConvolutionFunctions/arm_convolve_HWC_q15_basic.c"/>
         <file category="source" name="CMSIS/NN/Source/ConvolutionFunctions/arm_convolve_1x1_s8_fast.c"/>
         <file category="source" name="CMSIS/NN/Source/ConvolutionFunctions/arm_depthwise_conv_s8.c"/>
+        <file category="source" name="CMSIS/NN/Source/ConvolutionFunctions/arm_depthwise_conv_s16.c"/>
         <file category="source" name="CMSIS/NN/Source/ConvolutionFunctions/arm_convolve_fast_s16.c"/>
         <file category="source" name="CMSIS/NN/Source/ConvolutionFunctions/arm_convolve_HWC_q15_fast_nonsquare.c"/>
         <file category="source" name="CMSIS/NN/Source/ConvolutionFunctions/arm_convolve_s8.c"/>