增加ota文件系统编译方法；（注意每次swupdate_make_recovery_img需要删除根目录和./lichee/linux下的.config和.config.old）

target/allwinner/v851s3-fastboot_sl100_front/swupdate/sw-description

@@ -9,7 +9,7 @@ software =
         upgrade_recovery = {
             /* upgrade recovery */
             images: (
-                {
+                /*{
                     filename = "recovery";
                     device = "/dev/by-name/recovery";
                     installed-directly = true;
@@ -21,7 +21,7 @@ software =
                 {
                     filename = "boot0";
                     type = "awboot0";
-                }
+                }*/
             );
             /* change swu_mode to upgrade_kernel,boot_partition to recovery & reboot*/
             bootenv: (