[PATCH] image.bbclass: copy dtbs into a deploydir/subdirectory based on the image name

["nicusor.huhulea@siemens.com" <nicusor.huhulea@siemens.com>]

This fixes the build failures detailed in the https://groups.google.com/g/isar-users/c/Va0Ue-ISYeA and
https://groups.google.com/g/isar-users/c/PSGU_AcdPZ8
This adds the MACHINE variable to WICVARS, hence the need to reflect this change in
cip-core/scripts/lib/wic/plugins/source/efibootguard-boot.py


    Signed-off-by: Nicusor Huhulea <nicusor.huhulea@siemens.com>

diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
index 73f1d52c..9b98719b 100644
--- a/meta/classes/image.bbclass
+++ b/meta/classes/image.bbclass
@@ -377,16 +377,19 @@ do_copy_boot_files() {
         fi
     fi
 
-    for file in ${DTB_FILES}; do
-        dtb="$(find '${IMAGE_ROOTFS}/usr/lib' -type f \
-                    -iwholename '*linux-image-*/'${file} | head -1)"
-
-        if [ -z "$dtb" -o ! -e "$dtb" ]; then
-            die "${file} not found"
-        fi
+    if [ -n "${DTB_FILES}" ]; then
+        mkdir -p "${DEPLOYDIR}/${IMAGE_FULLNAME}.dtbs"
+        for file in ${DTB_FILES}; do
+            dtb="$(find '${IMAGE_ROOTFS}/usr/lib' -type f \
+                        -iwholename '*linux-image-*/'${file} | head -1)"
+
+            if [ -z "$dtb" -o ! -e "$dtb" ]; then
+                die "${file} not found"
+            fi
 
-        cp -f "$dtb" "${DEPLOYDIR}/"
-    done
+            cp -f "$dtb" "${DEPLOYDIR}/${IMAGE_FULLNAME}.dtbs"
+        done
+    fi
 }
 addtask copy_boot_files before do_rootfs_postprocess after do_rootfs_install
 
diff --git a/meta/classes/imagetypes_wic.bbclass b/meta/classes/imagetypes_wic.bbclass
index bce881ed..f0f1c438 100644
--- a/meta/classes/imagetypes_wic.bbclass
+++ b/meta/classes/imagetypes_wic.bbclass
@@ -107,7 +107,7 @@ WICVARS += "\
            ROOTFS_SIZE STAGING_DATADIR STAGING_DIR STAGING_LIBDIR TARGET_SYS TRANSLATED_TARGET_ARCH"
 
 # Isar specific vars used in our plugins
-WICVARS += "DISTRO DISTRO_ARCH"
+WICVARS += "DISTRO DISTRO_ARCH MACHINE"
 
 python do_rootfs_wicenv () {
     wicvars = d.getVar('WICVARS')