Add kissfft to makefile download, add hooks to include additional kernel srcs and kernel tests outside lite/micro/kernels.

PiperOrigin-RevId: 374755937
Change-Id: I61eda01aa8be01a4d226a8db44ecc4cbedad3391
diff --git a/tensorflow/lite/micro/tools/make/Makefile b/tensorflow/lite/micro/tools/make/Makefile
index e50f460..2f6119d 100644
--- a/tensorflow/lite/micro/tools/make/Makefile
+++ b/tensorflow/lite/micro/tools/make/Makefile
@@ -128,6 +128,7 @@
   -Wall \
   -Wextra \
   -Wstrict-aliasing \
+	-Wno-nonnull \
   -Wno-unused-parameter
 
 COMMON_FLAGS := \
@@ -390,6 +391,8 @@
 tensorflow/lite/micro/kernels/unpack.cc \
 tensorflow/lite/micro/kernels/zeros_like.cc
 
+include $(MAKEFILE_DIR)/additional_kernels.inc
+
 MICROLITE_TEST_HDRS := \
 $(wildcard tensorflow/lite/micro/testing/*.h)
 
@@ -584,6 +587,7 @@
   $(eval $(call add_third_party_download,$(GEMMLOWP_URL),$(GEMMLOWP_MD5),gemmlowp,))
   $(eval $(call add_third_party_download,$(RUY_URL),$(RUY_MD5),ruy,))
   $(eval $(call add_third_party_download,$(PERSON_MODEL_URL),$(PERSON_MODEL_MD5),person_model_grayscale,))
+  $(eval $(call add_third_party_download,$(KISSFFT_URL),$(KISSFFT_MD5),kissfft,patch_kissfft))
   RESULT := $(shell $(MAKEFILE_DIR)/person_detection_int8_download.sh ${MAKEFILE_DIR}/downloads $(CO_PROCESSOR))
   ifneq ($(RESULT), SUCCESS)
     $(error Something went wrong with the person detection int8 model download: $(RESULT))
@@ -828,6 +832,7 @@
   $(EXPLICITLY_SPECIFIED_TEST_SRCS),$(EXPLICITLY_SPECIFIED_TEST_HDRS)))
 endif
 
+include $(MAKEFILE_DIR)/additional_tests.inc
 
 # For all the tests that do not have any additional dependencies, we can
 # add a make target in a common way.
diff --git a/tensorflow/lite/micro/tools/make/additional_kernels.inc b/tensorflow/lite/micro/tools/make/additional_kernels.inc
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tensorflow/lite/micro/tools/make/additional_kernels.inc
diff --git a/tensorflow/lite/micro/tools/make/additional_tests.inc b/tensorflow/lite/micro/tools/make/additional_tests.inc
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tensorflow/lite/micro/tools/make/additional_tests.inc