zmk: Add Copyright and License for reuse compliance

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

meta-ohos-acts/recipes-zmk/zmk/zmk-native_0.5.bb

+# SPDX-FileCopyrightText: Huawei Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+
 SUMMARY = "Collection of reusable makefiles"
 LICENSE = "LGPLv3"
 LIC_FILES_CHKSUM = "file://LICENSE;md5=e6a600fd5e1d9cbde2d983680233ad02"