bblayers.conf.sample: Add meta-ohos-staging

We use this layer to store temporary fixes while upstream catches up.

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

flavours/linux/bblayers.conf.sample

@@ -19,6 +19,7 @@ BBLAYERS ?= " \
   ##OEROOT##/../meta-ohos/meta-ohos-core \
   ##OEROOT##/../meta-ohos/meta-ohos-acts \
   ##OEROOT##/../meta-ohos/meta-ohos-demo \
+  ##OEROOT##/../meta-ohos/meta-ohos-staging \
   ##OEROOT##/../meta-intel \
   ##OEROOT##/../meta-seco-intel \
   ##OEROOT##/../meta-freescale \