Get Logo URL to use on Login Page

I am trying to customize my login page and replace the WordPress logo.
Can you tell me how to programmatically get the url logo set with Enfold theme options, so I can set the background-image something like below?

In below, I want to get the code I need to put after the url and parentheses.

echo '<style type="text/css">
  .login h1 a { background-image: url('.get_bloginfo('template_directory').'/images/custom-login-logo.png) !important; }
  </style>';

Thank you!