openharmony-linux-demo-dashboard: Add ohos based distro configuration

This configuration inherits the ohos distro configuration but makes
configurations specific to the dashboard demo use-cases. For now we only
handle the HomeAssistant version requirements and set a custom hostname.

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

meta-ohos-demo/conf/distro/openharmony-linux-demo-dashboard.conf

+# Distro configuration for the dashboard demo
+
+require conf/distro/openharmony-linux.conf
+include conf/distro/include/ha-versions.inc
+
+DISTRO = "openharmony-linux-demo-dashboard"
+DISTRO_NAME = "OpenHarmony Dashboard Demo Linux Distro"
+
+# Custom hostnames for easy DNS resolution for this demo.
+# The gateway would run on a stm32mp1-av96 machine.
+hostname_base-files_stm32mp1-av96 = "demo-dashboard-gateway"
+
+# Avoid build warning(s) for ununsed extra partitions.
+ST_VENDORFS = "0"
+ST_USERFS = "0"