message: Update cmsis_nn readme
diff: @@ -24,13 +24,13 @@ mbed. Here's an example on how to do that. Start by generating an mbed project.
  ```
  make -f tensorflow/lite/micro/tools/make/Makefile OPTIMIZED_KERNEL_DIR=cmsis_nn \
  -generate_person_detection_mbed_project
  +generate_person_detection_int8_mbed_project
  ```
  Go into the generated mbed project folder, currently:
  ```
  -tensorflow/lite/micro/tools/make/gen/linux_x86_64/prj/person_detection_int8/mbed
  +tensorflow/lite/micro/tools/make/gen/linux_x86_64_default/prj/person_detection_int8/mbed
  ```
  and setup mbed.
  @@ -51,7 +51,7 @@ There's also a dependency to an old cmsis_gcc.h, which you can fix with the
  following:
  ```
  -tensorflow/lite/micro/tools/make/downloads/cmsis/CMSIS/Core/Include/\
  +cp tensorflow/lite/micro/tools/make/downloads/cmsis/CMSIS/Core/Include/\
  cmsis_gcc.h mbed-os/cmsis/TARGET_CORTEX_M/cmsis_gcc.h
  ```
  