CMSIS-NN: Add MVEI support for int16 max pooling (#1509)

Change-Id: Ia75af0245dbe471aae629110b53b0d0998afca2b
diff --git a/ARM.CMSIS.pdsc b/ARM.CMSIS.pdsc
index ce57db3..63a1d97 100644
--- a/ARM.CMSIS.pdsc
+++ b/ARM.CMSIS.pdsc
@@ -14,6 +14,7 @@
        - Changed return types of all API's
        - Support for int16 average pooling DSP implementation
        - Support for DSP extension optimization for int16 depthwise_conv
+       - Support for MVEI extension optimization for int16 max pooling
     </release>
     <release version="5.9.0" date="2022-05-02">
       CMSIS-Core(M): 5.6.0