remove grafana dashboards (#311)

* remove grafana dashboards

* link to 1.4.0 branch

Author: pensan-tou

grafana/README.md

@@ -1,7 +1,3 @@
 # Grafana Dashboards
 
-### Variables
-
-Variables can be configured at any time in each dashboard's **Settings > Variables** section.
-
-**g_metrics_prefix**: string to prefix names of metrics queries (e.g. gpu_gfx_activity -> amd_gpu_gfx_activity)
+Grafana dashboards can be found in the [ROCm/device-metrics-exporter](https://github.com/ROCm/device-metrics-exporter) repository under the [grafana](https://github.com/ROCm/device-metrics-exporter/tree/release-v1.4.0/grafana) directory.