oniro-freertos.conf: Add distro for freeRTOS as we have for other OS'

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

meta-oniro-core/conf/distro/oniro-freertos.conf

+# SPDX-FileCopyrightText: Huawei Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+require conf/distro/include/oniro.inc
+require conf/distro/freertos.conf
+
+DISTRO = "oniro-freertos"
+DISTRO_NAME = "Oniro Project Base FreeRTOS Distro"
+DISTRO_VERSION = "1.0.0-beta"