GitLab

 - Remove out-dated information about the use of printf() in the
   function comment.

 - Make the argument const, as the function doesn't need to modify it.

 - Rename the function into bl1_print_bl31_ep_info() to make its
   purpose clearer.

Change-Id: I2a9d215a37f0ec11aefce0c5c9e050473b7a6b25