CMSIS-DSP: Added ARM_MATH_AUTOVECTORIZE and AUTOVECTORIZE to cmake

It is to provide more control and to disable
intrinsics version of some kernels when the C code is simple enough to
benefit from vectorization.

Since the result is compiler dependent, this option is optional.
(And it is not yet added to the source files).

Compilation flags may have to be tuned (-O3 for instance ...)
diff --git a/CMSIS/DSP/Source/configDsp.cmake b/CMSIS/DSP/Source/configDsp.cmake
index ccdf5cb..b472be0 100644
--- a/CMSIS/DSP/Source/configDsp.cmake
+++ b/CMSIS/DSP/Source/configDsp.cmake
@@ -18,8 +18,14 @@
   target_compile_definitions(${project} PRIVATE ARM_MATH_MATRIX_CHECK)
 endif()
 
+if (AUTOVECTORIZE)
+    target_compile_definitions(${project} PRIVATE ARM_MATH_AUTOVECTORIZE) 
+endif()
+
 if (NEON OR NEONEXPERIMENTAL)
     target_include_directories(${project} PRIVATE "${root}/CMSIS/DSP/ComputeLibrary/Include")
 endif()
 
+
+
 endfunction()
\ No newline at end of file