Remove sph flag (#143)

## Purpose
Remove sph flag to avoid permissions error when simulator is deployed

## Does this introduce a breaking change?
<!-- Mark one with an "x". -->
```
[ ] Yes
[x] No
```

## Pull Request Type
What kind of change does this Pull Request introduce?

<!-- Please check the one that applies to this PR using "x". -->
```
[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[x] Documentation content changes
[ ] Other... Please describe:
```

Author: dominicbetts

samples/quickstarts/opc-plc-deployment.yaml

@@ -17,12 +17,11 @@ spec:
     spec:
       containers:
       - name: opc-plc
-        image: mcr.microsoft.com/iotedge/opc-plc:2.12.39
+        image: mcr.microsoft.com/iotedge/opc-plc:latest
         args:
           - "--ph=opcplc-000000"
           - "--cdn=opcplc-000000"
           - "--ut"
-          - "--sph"
           - "--sn=5"
           - "--sr=10"
           - "--fn=10"

samples/quickstarts/opc-plc-tutorial-deployment.yaml

@@ -17,13 +17,12 @@ spec:
     spec:
       containers:
       - name: opc-plc
-        image: mcr.microsoft.com/iotedge/opc-plc:2.12.39
+        image: mcr.microsoft.com/iotedge/opc-plc:latest
         args:
           - "--plchostname=opcplc-000000"
           - "--portnum=50000"
           - "--certdnsnames=opcplc-000000"
           - "--unsecuretransport"
-          - "--showpnjsonph"
           - "--slownodes=5"
           - "--slowrate=10"
           - "--fastnodes=10"