porting/nuttx; Fix error: unrecognized command-line option '-m32'

-m32 is supported by x64 toolchain, not arm-none-eabi-gcc

Signed-off-by: Xiang Xiao <[email protected]>

porting/examples/nuttx/Make.defs

@@ -48,8 +48,7 @@ INC = \
 
 INCLUDES := $(addprefix -I, $(INC))
 
-CFLAGS +=                    \
-    $(NIMBLE_CFLAGS)        \
+CFLAGS +=                   \
     $(INCLUDES)             \
     $(TINYCRYPT_CFLAGS)     \
     -DNIMBLE_CFG_CONTROLLER=0 -DOS_CFG_ALIGN_4=4 -DOS_CFG_ALIGNMENT=4 \