[fpu] have the arch layers set WITH_NO_FPU based on the cpu

This will generally turn off more FPU codegen, even if its using
software fallback unless the project/target/platform selects a cpu that
has FPU support. This also turns off a few blocks of test code and the
upcoming floating point printf if it's not present on the arch.

This may break projects that were compiling for say cortex-m0 but
expected FPU code to be present. If so it should be pretty easy to
override it, but not going to add that yet unless it's necessary.

platform/cc13xx/rules.mk

@@ -23,8 +23,7 @@ MODULE_DEPS += \
 	arch/arm/arm-m/systick \
 	platform/cc13xx/cc13xxware
 
-GLOBAL_COMPILEFLAGS += -DWITH_NO_FP=1
-#GLOBAL_COMPILEFLAGS +=  -DDISABLE_DEBUG_OUTPUT=1
+#GLOBAL_DEFINES += DISABLE_DEBUG_OUTPUT=1
 
 include make/module.mk