update bridge deployment for CNSA documentation

Author: Helene

docs/BUILDING_DOCKER_IMAGE.md

@@ -12,7 +12,14 @@
 ```
 
 
-2. Create the bridge container image
+2. Switch to the 6.1 branch
+
+```shell
+# git checkout 6.1
+```
+
+
+3. Create the bridge container image
 
 ```shell
 # cd grafana_bridge/source

docs/grafana_bridge_deployment_ocp.md

@@ -5,6 +5,7 @@
 ### Dependencies
 This instructions could be used for: 
 - IBM Spectrum Scale Container Native Storage Access(CNSA) devices having minimum release level 5.1.0.1 and above
+- IBM Spectrum Scale bridge for Grafana *version 6.1.2* (Checkout the branch 6.1)
 
 
 1. Follow the [instructions](/docs/BUILDING_DOCKER_IMAGE.md) and create the IBM Spectrum Scale bridge for Grafana image