Fix build issues in micro_speech project

* Remove non-existant `arm_cmplx_mag_squared_q10p6.c/h` from
  "tensorflow/lite/micro/examples/micro_speech/CMSIS/Makefile.inc",
  which cause the build of micro_speech project to fail.
  See also: tensorflow#36444

* Remove unnecessary `third_party/CMSIS_ext/README.md` from `CMSIS_PREPROCESSOR_HDRS`
  in "tensorflow/lite/micro/examples/micro_speech/CMSIS/Makefile.inc",
  which cause the build of micro_speech project to fail.

* Update MBED version to mbed-os-6.0.0-alpha-3: this fixes the issues related
  to `arm_mult_q15.c` in the ARM math library when building the micro_speech
  project.
  See also:
  1. tensorflow#37930
  2. ARMmbed/mbed-os#12055

Author: biagiom

tensorflow/lite/micro/examples/micro_speech/CMSIS/Makefile.inc

@@ -12,13 +12,11 @@ ifneq ($(filter CMSIS,$(ALL_TAGS)),)
 
   CMSIS_PREPROCESSOR_SRCS := \
     tensorflow/lite/micro/examples/micro_speech/CMSIS/hanning.cc \
-    tensorflow/lite/micro/examples/micro_speech/CMSIS/sin_1k.cc \
+    tensorflow/lite/micro/examples/micro_speech/CMSIS/sin_1k.cc
 
   CMSIS_PREPROCESSOR_HDRS := \
     tensorflow/lite/micro/examples/micro_speech/CMSIS/hanning.h \
-    tensorflow/lite/micro/examples/micro_speech/CMSIS/sin_1k.h \
-    third_party/CMSIS_ext/README.md \
-    third_party/CMSIS_ext/arm_cmplx_mag_squared_q10p6.h
+    tensorflow/lite/micro/examples/micro_speech/CMSIS/sin_1k.h
 
   PREPROCESSOR_TEST_SRCS += $(CMSIS_PREPROCESSOR_SRCS)
   PREPROCESSOR_TEST_HDRS += $(CMSIS_PREPROCESSOR_HDRS)
@@ -33,7 +31,6 @@ ifneq ($(filter CMSIS,$(ALL_TAGS)),)
   MICRO_SPEECH_HDRS += $(CMSIS_PREPROCESSOR_HDRS)
 
   THIRD_PARTY_CC_SRCS += \
-    $(MAKEFILE_DIR)/downloads/CMSIS_ext/arm_cmplx_mag_squared_q10p6.c \
     $(MAKEFILE_DIR)/downloads/cmsis/CMSIS/DSP/Source/BasicMathFunctions/arm_mult_q15.c \
     $(MAKEFILE_DIR)/downloads/cmsis/CMSIS/DSP/Source/TransformFunctions/arm_bitreversal.c \
     $(MAKEFILE_DIR)/downloads/cmsis/CMSIS/DSP/Source/TransformFunctions/arm_rfft_init_q15.c \

tensorflow/lite/micro/tools/make/templates/mbed-os.lib.tpl

@@ -1 +1 @@
-https://github.com/ARMmbed/mbed-os/#8ef742a49c1682f9ef3ba50148b871e38c3866cc
+https://github.com/ARMmbed/mbed-os/#532654ebb31c7bf79601042a6fa976b85532ef47