openharmony-linux.conf: Inherit the ohos-sanity bbclass

As the ohos-sanity bbclass is not kernel-specific, the inclusion is done
through an include file.

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

meta-ohos-core/conf/distro/include/openharmony.inc

+# SPDX-FileCopyrightText: Huawei Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+INHERIT += "ohos-sanity"

meta-ohos-core/conf/distro/openharmony-linux.conf

@@ -2,6 +2,7 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
+require conf/distro/include/openharmony.inc
 require conf/distro/poky.conf
 
 DISTRO = "openharmony-linux"