helm: Avoid error in IDE due to .range keyword

As range is a keyword in jinja template, using the expression with usual
attribute name (e.g. .Values.nodePort.range) will cause the error in IDE.
This issue makes it hard for deployment helm for normal operation like
checking where the flag is used.

This commit is to use alternative way to get around the issue with get
function.

Testing was done as per below

```
$ cat temp_values.yaml
nodePort:
  range: "30000,32767"
$ helm template cilium install/kubernetes/cilium -f temp_values.yaml | grep node-port-range
  node-port-range: "30000,32767"
  enable-auto-protect-node-port-range: "true"
```

Signed-off-by: Tam Mach <tam.mach@cilium.io>

install/kubernetes/cilium/templates/cilium-configmap.yaml

@@ -650,7 +650,7 @@ data:
   enable-node-port: {{ .Values.nodePort.enabled | quote }}
 {{- end }}
 {{- if hasKey .Values.nodePort "range" }}
-  node-port-range: {{ .Values.nodePort.range | quote }}
+  node-port-range: {{ get .Values.nodePort "range" | quote }}
 {{- end }}
 {{- if hasKey .Values.nodePort "directRoutingDevice" }}
   direct-routing-device: {{ .Values.nodePort.directRoutingDevice | quote }}