tests/pkg_utensor: increase main threads stack size

The MPU based stack guard is very unpleased by the stack overflow
happening during the test. The increase in stack size makes the MPU
stack guard happy again.

tests/pkg_utensor/Makefile

@@ -11,10 +11,4 @@ EXTERNAL_MODULE_DIRS += external_modules
 
 include $(RIOTBASE)/Makefile.include
 
-# The application requires a little more stacksize on ARM when building with
-# LLVM
-ifneq (,$(filter arch_arm,$(FEATURES_USED)))
-  ifeq (llvm,$(TOOLCHAIN))
-    CFLAGS += -DTHREAD_STACKSIZE_MAIN=2048
-  endif
-endif
+CFLAGS += -DTHREAD_STACKSIZE_MAIN=THREAD_STACKSIZE_LARGE