fixes Makefiles for mbed_lpc1768 board

boards/mbed_lpc1768/Makefile

@@ -18,6 +18,7 @@ $(BINDIR)$(ARCH): $(OBJ)
 
 # compile and generate dependency info
 $(BINDIR)%.o: %.c
+	mkdir -p $(BINDIR)
 	$(CC) $(CFLAGS) $(INCLUDES) $(BOARDINCLUDE) $(PROJECTINCLUDE) $(CPUINCLUDE) -c $*.c -o $(BINDIR)$*.o
 	$(CC) $(CFLAGS) $(INCLUDES) $(BOARDINCLUDE) $(PROJECTINCLUDE) $(CPUINCLUDE) -MM $*.c > $(BINDIR)$*.d
 	@printf "$(BINDIR)"|cat - $(BINDIR)$*.d > /tmp/riot_out && mv /tmp/riot_out $(BINDIR)$*.d

boards/mbed_lpc1768/Makefile.include

@@ -12,7 +12,7 @@ export LINK = $(PREFIX)gcc
 export SIZE = $(PREFIX)size
 export OBJCOPY = $(PREFIX)objcopy
 #LINKFLAGS =  -g3 -ggdb -mcpu=cortex-m3 $(FPU_USAGE) -mlittle-endian -static -lgcc -mthumb -mthumb-interwork -nostartfiles -T$(RIOTCPU)/$(CPU)/LPC1768.ld
-LINKFLAGS = -mcpu=cortex-m3 -mthumb -Wl,--gc-sections,--cref --specs=nano.specs -lc -lgcc -lnosys -T$(RIOTCPU)/$(CPU)/LPC1768.ld -nostartfiles
+LINKFLAGS = -mcpu=cortex-m3 -mthumb -Wl,--gc-sections,--cref -lc -lgcc -lnosys -T$(RIOTCPU)/$(CPU)/LPC1768.ld -nostartfiles
 
 ifeq ($(strip $(PORT)),)
 	export PORT = /dev/ttyUSB0