Fixed password field options argument

Current implementation of `password()` method uses a `$value` parameter which is not present in the [upstream implementation](https://github.com/laravel/framework/blob/4.2/src/Illuminate/Html/FormBuilder.php#L268).

That causes your options to be ignored when you use the official syntax `Form::password('name', $optionsArray)` .

This PR just removes the $value parameter which wasn't used anyway.