u-boot: fix dependency for host mkimage

target/u-boot/Makefile.in

@@ -186,7 +186,7 @@ $(BINARIES_DIR)/$(U_BOOT_BIN): $(U_BOOT_DIR)/$(U_BOOT_BIN)
 	cp -dpf $(U_BOOT_DIR)/$(U_BOOT_BIN) $(BINARIES_DIR)/$(U_BOOT_TARGET_BIN)
 	(cd $(BINARIES_DIR); ln -s $(U_BOOT_TARGET_BIN) $(U_BOOT_BIN))
 
-$(U_BOOT_TOOLS):	$(U_BOOT_DIR)/tools/$(U_BOOT_TOOLS_BIN)
+$(U_BOOT_TOOLS): $(U_BOOT_DIR)/$(U_BOOT_BIN)
 	cp -dpf $(U_BOOT_DIR)/tools/$(U_BOOT_TOOLS_BIN) $(STAGING_DIR)/usr/bin/
 
 $(TARGET_DIR)/usr/bin/mkimage: $(U_BOOT_DIR)/$(U_BOOT_BIN)