conf:common: Add MACHINE_RELEASE_ARTIFACTS for CI

conf/machine/include/mediatek-common.inc

@@ -117,7 +117,7 @@ MACHINE_EXTRA_RRECOMMENDS:append = " ${@bb.utils.contains("DISTRO_FEATURES", "op
 # Genio uses the different installation scheme and requires extra files.
 # devicetree directory contains overlays to be listed by genio-flash 
 MACHINE_RELEASE_ARTEFACTS = " \
-    ${@' '.join(['devicetree/' + dtbo.split('/')[-1] for dtbo in d.getVar('KERNEL_DTBO', True).split()])} \
+    ${@' '.join(['devicetree/' + dtbo.split('/')[-1] for dtbo in KERNEL_DTBO.split()])} \
     bl2.img \
     bootassets.vfat \
     capsule.vfat \