MLECO-1982: Update to using latest ethos-u embedded components

Change-Id: I744a4eb2553207004c9403b956e5bd9e9b352bfb
Signed-off-by: Isabella Gottardi <isabella.gottardi@arm.com>
diff --git a/scripts/make/cortex_m_ethos_eval_makefile.inc b/scripts/make/cortex_m_ethos_eval_makefile.inc
index dbb460d..407bc85 100644
--- a/scripts/make/cortex_m_ethos_eval_makefile.inc
+++ b/scripts/make/cortex_m_ethos_eval_makefile.inc
@@ -117,12 +117,6 @@
     MICROLITE_LIBS := $(filter-out -lm,$(MICROLITE_LIBS))
 
   else ifeq ($(TOOLCHAIN), gcc)
-    export PATH := $(MAKEFILE_DIR)/downloads/gcc_embedded/bin/:$(PATH)
-    DOWNLOAD_RESULT := $(shell $(MAKEFILE_DIR)/arm_gcc_download.sh ${MAKEFILE_DIR}/downloads)
-    ifneq ($(DOWNLOAD_RESULT), SUCCESS)
-      $(error Something went wrong with the GCC download: $(DOWNLOAD_RESULT))
-    endif
-
     TARGET_TOOLCHAIN_PREFIX := arm-none-eabi-
 
     FLAGS_GCC = -mcpu=$(GCC_TARGET_ARCH) -mfpu=auto
@@ -133,6 +127,16 @@
     $(error "TOOLCHAIN=$(TOOLCHAIN) is not supported.")
   endif
 
+# TODO(#47718): resolve warnings.
+CXX_OMIT_ERRORS = \
+  -Wno-implicit-fallthrough \
+  -Wno-unused-variable
+
+# TODO: Remove when Arm Ethos-U NPU driver is updated to version > 21.05
+CC_OMIT_ERRORS = \
+  ${CXX_OMIT_ERRORS} \
+  -Wno-int-conversion
+
   PLATFORM_FLAGS = \
     -DTF_LITE_MCU_DEBUG_LOG \
     -mthumb \
@@ -147,7 +151,7 @@
     $(TARGET_SPECIFIC_FLAGS)
 
   # Common + C/C++ flags
-  CXXFLAGS += $(PLATFORM_FLAGS)
-  CCFLAGS += $(PLATFORM_FLAGS)
+  CXXFLAGS += $(PLATFORM_FLAGS) ${CXX_OMIT_ERRORS}
+  CCFLAGS += $(PLATFORM_FLAGS) ${CC_OMIT_ERRORS}
 
 endif