examples: enable gc-sections option

This fixes building time.c when unreferenced functions are added.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
diff --git a/examples/api/Makefile b/examples/api/Makefile
index 4d68340..33cc91b 100644
--- a/examples/api/Makefile
+++ b/examples/api/Makefile
@@ -53,7 +53,7 @@
 #########################################################################
 
 $(OUTPUT):	$(OBJS)
-		$(LD) -Ttext $(LOAD_ADDR) -o $@ $^ $(PLATFORM_LIBS)
+		$(LD) --gc-sections -Ttext $(LOAD_ADDR) -o $@ $^ $(PLATFORM_LIBS)
 		$(OBJCOPY) -O binary $@ $(OUTPUT).bin 2>/dev/null
 
 # Rule to build generic library C files