kwin: add workaround for UNPACKDIR migration

recipes-plasma/kwin.inc

@@ -76,11 +76,14 @@ inherit pkgconfig
 # TODO skip inherit of cmake_plasma for now because it leads to build errors for native package
 
 do_install:append() {
+    # compatibility workaround for Yocto versions older than Styhead
+    [ -z ${UNPACKDIR+x} ] && UNPACKDIR=${WORKDIR}
+
     # dirty workaround for aurora crash on Wayland
     rm -rf ${D}/${libdir}/plugins/org.kde.kdecoration2/
 
     install -d ${D}/${sysconfdir}/xdg
-    install -m 644 ${WORKDIR}/kwinrc ${D}/${sysconfdir}/xdg/kwinrc
+    install -m 644 ${UNPACKDIR}/kwinrc ${D}/${sysconfdir}/xdg/kwinrc
 }
 
 FILES_SOLIBSDEV = ""