Add instruction set extension by processor validation.

cicm_web/Areas/Admin/Views/InstructionSetExtensionsByProcessor/Create.cshtml

@@ -22,6 +22,9 @@
                         class="form-control"
                         asp-items="ViewBag.ProcessorId">
                 </select>
+                <span asp-validation-for="ProcessorId"
+                      class="text-danger">
+                </span>
             </div>
             <div class="form-group">
                 <label asp-for="Extension"
@@ -31,6 +34,9 @@
                         class="form-control"
                         asp-items="ViewBag.ExtensionId">
                 </select>
+                <span asp-validation-for="ExtensionId"
+                      class="text-danger">
+                </span>
             </div>
             <div class="form-group">
                 <input class="btn btn-primary"
@@ -43,4 +49,8 @@
             </div>
         </form>
     </div>
-</div>
+</div>
+
+@section Scripts {
+    @{ await Html.RenderPartialAsync("_ValidationScriptsPartial"); }
+}