treewide: Change .*GPL.*+ licenses to SPDX compatible identifier

The CONTRIBUTING.md requests an (or multiple) SPDX identifier for GPL
licenses. But a lot of packages did use a different, non-SPDX style with a
"+" at the end instead of "-or-later".

Signed-off-by: Sven Eckelmann <sven@narfation.org>

utils/tio/Makefile

@@ -9,14 +9,14 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=tio
 PKG_VERSION:=1.32
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=https://github.com/tio/tio/releases/download/v$(PKG_VERSION)
 PKG_HASH:=a8f5ed6994cacb96780baa416b19e5a6d7d67e8c162a8ea4fd9eccd64984ae44
 
 PKG_MAINTAINER:=
-PKG_LICENSE:=GPL-2.0+
+PKG_LICENSE:=GPL-2.0-or-later
 PKG_LICENSE_FILES:=COPYING
 
 PKG_FIXUP:=autoreconf