Compile with -ffp-mode=full for armclang (#2517)

This is needed due to multiple uses of NaN and Infinity which is not supported with the default -ffp-mode=std.

BUG=#2518

tensorflow/lite/micro/tools/make/Makefile

diff --git a/tensorflow/lite/micro/tools/make/Makefile b/tensorflow/lite/micro/tools/make/Makefile
index 8eaed42..90b0c29 100644
--- a/tensorflow/lite/micro/tools/make/Makefile
+++ b/tensorflow/lite/micro/tools/make/Makefile
@@ -860,6 +860,7 @@
 # These are microcontroller-specific rules for converting the ELF output
 # of the linker into a binary image that can be loaded directly.
 ifeq ($(TOOLCHAIN), armclang)
+  CXXFLAGS += -ffp-mode=full
   FROMELF := ${TARGET_TOOLCHAIN_ROOT}$(TARGET_TOOLCHAIN_PREFIX)fromelf
   $(BINDIR)%.bin: $(BINDIR)%
 		@mkdir -p $(dir $@)

tensorflow/lite/micro/tools/make/targets/cortex_m_corstone_300_makefile.inc

diff --git a/tensorflow/lite/micro/tools/make/targets/cortex_m_corstone_300_makefile.inc b/tensorflow/lite/micro/tools/make/targets/cortex_m_corstone_300_makefile.inc
index 64d0662..c0ae058 100644
--- a/tensorflow/lite/micro/tools/make/targets/cortex_m_corstone_300_makefile.inc
+++ b/tensorflow/lite/micro/tools/make/targets/cortex_m_corstone_300_makefile.inc
@@ -97,8 +97,7 @@
   FLAGS_ARMC = \
     --target=arm-arm-none-eabi \
     -Wno-unused-private-field \
-    -mcpu=$(MCPU_OPTION) \
-    -ffp-mode=full
+    -mcpu=$(MCPU_OPTION)
 
   # Pass comma separated linker options to armlink
   ARMC6_LDFLAGS += -Wl,--strict,--summary_stderr,--info,summarysizes,--map