Remove type hinting in toRoute

`toRoute()` used in `action()` and `route()` which can accept simple value __or__ array. Thus the
```php
link_to_route('resource.edit', 'Edit', 1);
```
will throw an exception `Argument 2 passed to Illuminate\Routing\UrlGenerator::toRoute() must be of the type array, integer given`.
Merge pull request #6132 from jhaoda/master

[5.0] Remove Type Hinting In toRoute