fix: Specify PriorityClass for Node Feature Discovery components (#1041)

**What problem does this PR solve?**:
NFD components were missing a PriorityClass.

**Which issue(s) this PR fixes**:
Fixes
- https://jira.nutanix.com/browse/NCN-1005633
- https://jira.nutanix.com/browse/NCN-105634

**How Has This Been Tested?**:
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Author: dlipovetsky

charts/cluster-api-runtime-extensions-nutanix/addons/nfd/values-template.yaml

@@ -1,3 +1,5 @@
+priorityClass: system-node-critical
+
 master:
   extraLabelNs:
     - nvidia.com