[openwrt/openwrt] busybox: use $(AUTORELEASE) and SPDX

[LEDE Commits]

zorun pushed a commit to openwrt/openwrt.git, branch openwrt-21.02:
https://git.openwrt.org/6b6bcca1a05315c019eb55bec2b460a54c65ba1e

commit 6b6bcca1a05315c019eb55bec2b460a54c65ba1e
Author: Paul Spooren <mail at aparcar.org>
AuthorDate: Tue May 18 15:36:10 2021 +0200

    busybox: use $(AUTORELEASE) and SPDX
    
    use AUTORELEASE since BusyBox is often updaten and PKG_RELEASE is not
    consistently bumped. Also use SPDX license headers to be machine
    readable and bump the copyright year to 2021.
    
    Signed-off-by: Paul Spooren <mail at aparcar.org>
    (cherry picked from commit 25fdb42249aef7b5eb53675f82f0091c532bf90c)
---
 package/utils/busybox/Makefile | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/package/utils/busybox/Makefile b/package/utils/busybox/Makefile
index 475a154fa3..0d5e420943 100644
--- a/package/utils/busybox/Makefile
+++ b/package/utils/busybox/Makefile
@@ -1,15 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 #
-# Copyright (C) 2006-2020 OpenWrt.org
-#
-# This is free software, licensed under the GNU General Public License v2.
-# See /LICENSE for more information.
-#
+# Copyright (C) 2006-2021 OpenWrt.org
 
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=busybox
 PKG_VERSION:=1.33.1
-PKG_RELEASE:=1
+PKG_RELEASE:=$(AUTORELEASE)
 PKG_FLAGS:=essential
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.bz2