Adjusted cc65 compiler options to recent cc65 option handling change.
@@ -67,7 +67,7 @@ AR = ar65
# The apps coming with Contiki run even on a 0x100 byte stack.
ASFLAGS = -t $(TARGET)
-CFLAGS += -t $(TARGET) -Or -W -unused-param
+CFLAGS += -t $(TARGET) -Ors -W -unused-param
LDFLAGS = -t $(TARGET) -m contiki-$(TARGET).map -D __STACKSIZE__=0x200
AROPTS = a
