This is a preparation for the next patches which will move the stuff
from uart_open and uart_close/hangup here. Then we will use
tty_port_* helpers.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>