softbus: Add Copyright and License for reuse compliance

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

meta-ohos-foundation/recipes-softbus/softbus/softbus_git.bb

+# SPDX-FileCopyrightText: Huawei Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+
 SUMMARY = "OHOS Softbus"
 DESCRIPTION = "OHOS communication utility for distributed services"
 LICENSE = "Apache-2.0"