add frequency control to dynamic config

resources/views/device/add.blade.php

@@ -31,6 +31,20 @@
                             </div>
                         </div>
 
+                        <div class="form-group row">
+                            <label for="freq" class="col-md-4 col-form-label text-md-right">{{ __('Polling Frequency') }}</label>
+
+                            <div class="col-md-6">
+                                <input id="freq" type="text" class="form-control{{ $errors->has('freq') ? ' is-invalid' : '' }}" name="freq" value="{{ old('freq') }}" placeholder="15" required autofocus>
+
+                                @if ($errors->has('freq'))
+                                    <span class="invalid-feedback" role="alert">
+                                    <strong>{{ $errors->first('freq') }}</strong>
+                                </span>
+                                @endif
+                            </div>
+                        </div>
+
                         <div class="form-group row">
                             <label for="camera" class="col-md-4 col-form-label text-md-right">{{ __('Camera Device Stream') }}</label>