u-boot-stm32mp-extlinux: Deploy extlinux configuration

This allows us to use IMAGE_BOOT_FILES to include these files in a
image.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

meta-ohos-core/recipes-bsp/u-boot/u-boot-stm32mp-extlinux.bbappend

+# SPDX-FileCopyrightText: Huawei Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+inherit deploy
+
+do_deploy[sstate-outputdirs] = "${DEPLOY_DIR_IMAGE}/bootloader/extlinux"
+do_deploy() {
+    # Deploy files too so wic can pick them up from DEPLOYDIR
+    if ! [ -z "$(ls -A ${B})" ]; then
+        cp -r --reflink=auto ${B}/* ${DEPLOYDIR}
+    fi
+}
+addtask deploy before do_build after do_compile