TTY:console: update document console.txt

Update Documentatin/console/console.txt to
reflect the following changes:

take_over_console|register_con_driver|unregister_con_driver|bind_con_driver
had gone, they had been replace by the new caller hold console lock version,
do_take_over_console|do_register_con_driver|do_unregister_con_driver|do_bind_con_driver.

This patch also fix a place include wrong description about give_up_console.

Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>