fix spurious ifxmips u-boot build errors

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@11387 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/linux/ifxmips/image/u-boot/Makefile

@@ -22,6 +22,7 @@ include $(INCLUDE_DIR)/package.mk
 
 define Build/Compile
 	cp -r ./files/* $(PKG_BUILD_DIR)
+	find $(PKG_BUILD_DIR) -name .svn | $(XARGS) rm -rf
 	cd $(PKG_BUILD_DIR);chmod a+x build_danube.sh;./build_danube.sh
 endef