hvc_console: Add tty driver flag TTY_DRIVER_RESET_TERMIOS

After a tty hangup() or close() operation, processes might not reset the
termio settings to a sane state. In order to reset the termios to its
default settings the tty driver flag TTY_DRIVER_RESET_TERMIOS has been added.

TTY driver flag description from include/linux/tty_driver.h:
	TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the
	  termios setting when the last process has closed the device.
	  Used for PTY's, in particular.
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

drivers/char/hvc_console.c

@@ -796,7 +796,7 @@ static int hvc_init(void)
 	drv->minor_start = HVC_MINOR;
 	drv->type = TTY_DRIVER_TYPE_SYSTEM;
 	drv->init_termios = tty_std_termios;
-	drv->flags = TTY_DRIVER_REAL_RAW;
+	drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
 	tty_set_operations(drv, &hvc_ops);
 
 	/* Always start the kthread because there can be hotplug vty adapters