configurations: nvidia_gb200: add sensor poll rate

Sensor polling rate for the Nvidia MCTP VDM device can be configured
in entity manager. This config is optional.

Signed-off-by: Deepak Kodihalli <deepak.kodihalli.83@gmail.com>
Change-Id: I10c45e49f519a797fb013255f14a7b78e2aa9bfa
diff --git a/schemas/nvidia.json b/schemas/nvidia.json
index fbcf746..b03bb27 100644
--- a/schemas/nvidia.json
+++ b/schemas/nvidia.json
@@ -8,6 +8,10 @@
                     "description": "A recognisable name for the device",
                     "type": "string"
                 },
+                "PollRate": {
+                    "description": "Poll the device at this rate, specified in milliseconds, to fetch sensors",
+                    "type": "number"
+                },
                 "Type": {
                     "type": "string",
                     "const": "NvidiaMctpVdm"