amlogic: use ftdir with N2/N2+ and C4/HC4

projects/Amlogic/bootloader/mkimage

@@ -44,6 +44,18 @@ EOF
   mcopy -s -o "${LE_TMP}/extlinux" ::
 }
 
+mkimage_extlinux_fdtdir(){
+  echo "image: copying exlinux.conf"
+  mkdir -p "${LE_TMP}/extlinux"
+  cat << EOF > "${LE_TMP}/extlinux/extlinux.conf"
+LABEL ${DISTRO}
+  LINUX /${KERNEL_NAME}
+  FDTDIR /
+  APPEND boot=LABEL=${DISTRO_BOOTLABEL} disk=LABEL=${DISTRO_DISKLABEL} quiet ${EXTRA_CMDLINE}
+EOF
+  mcopy -s -o "${LE_TMP}/extlinux" ::
+}
+
 mkimage_dtb(){
   if [ "$DTB" != "@@DTB_NAME@@" ]; then
     echo "image: copying device tree"
@@ -72,6 +84,11 @@ case "${UBOOT_SYSTEM}" in
     mkimage_bootini
     mkimage_dtb
     ;;
+  odroid-n2|odroid-c4)
+    mkimage_uboot
+    mkimage_extlinux_fdtdir
+    mkimage_dtb
+    ;;
   bananapi*|khadas*|lafrite|lepotato|nanopi-k2|odroid*|radxa*|wetek*)
     mkimage_uboot
     mkimage_extlinux