tty: Replace ASYNC_SUSPENDED bit and update atomically

Replace ASYNC_SUSPENDED bit in the tty_port::flags field with
TTY_PORT_SUSPENDED bit in the tty_port::iflags field. Introduce helpers
tty_port_set_suspended() and tty_port_suspended() to abstract
atomic bit ops.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 2471380..9336067 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -249,7 +249,7 @@
 	 * a DCD drop (hangup) at just the right time.  Clear suspended bit so
 	 * we don't try to resume a port that has been shutdown.
 	 */
-	clear_bit(ASYNCB_SUSPENDED, &port->flags);
+	tty_port_set_suspended(port, 0);
 
 	/*
 	 * Free the transmit buffer page.
@@ -2007,7 +2007,7 @@
 		const struct uart_ops *ops = uport->ops;
 		int tries;
 
-		set_bit(ASYNCB_SUSPENDED, &port->flags);
+		tty_port_set_suspended(port, 1);
 		clear_bit(ASYNCB_INITIALIZED, &port->flags);
 
 		spin_lock_irq(&uport->lock);
@@ -2088,7 +2088,7 @@
 			console_start(uport->cons);
 	}
 
-	if (port->flags & ASYNC_SUSPENDED) {
+	if (tty_port_suspended(port)) {
 		const struct uart_ops *ops = uport->ops;
 		int ret;
 
@@ -2118,7 +2118,7 @@
 			}
 		}
 
-		clear_bit(ASYNCB_SUSPENDED, &port->flags);
+		tty_port_set_suspended(port, 0);
 	}
 
 	mutex_unlock(&port->mutex);