treewide: fix GPLv2+ obsolete-license warnings

The LICENSE string 'GPLv2+' is considered obsolete by Yocto and raises a
warning.  Switch them too the accepted tag 'GPL-2.0-or-later'.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I88c639dbb45762e2e019a3503f1f1930b65c09d6
diff --git a/meta-phosphor/recipes-phosphor/video/fbterm_git.bb b/meta-phosphor/recipes-phosphor/video/fbterm_git.bb
index 662c9cc..568bbc6 100644
--- a/meta-phosphor/recipes-phosphor/video/fbterm_git.bb
+++ b/meta-phosphor/recipes-phosphor/video/fbterm_git.bb
@@ -1,5 +1,5 @@
 HOMEPAGE = "https://github.com/jk-ozlabs/fbterm"
-LICENSE = "GPLv2+"
+LICENSE = "GPL-2.0-or-later"
 
 SRC_URI += "git://github.com/jk-ozlabs/fbterm.git;nobranch=1;protocol=https"
 SRC_URI += "file://fb.modes"