serial: 8250: Revert "drop lockdep annotation from serial8250_clear_IER()"

The 8250 driver no longer depends on @oops_in_progress and
will no longer violate the port->lock locking constraints.

This reverts commit 3d9e6f5.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20250107212702.169493-7-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: jogness

drivers/tty/serial/8250/8250_port.c

@@ -726,6 +726,9 @@ static void __serial8250_clear_IER(struct uart_8250_port *up)
 
 static inline void serial8250_clear_IER(struct uart_8250_port *up)
 {
+	/* Port locked to synchronize UART_IER access against the console */
+	lockdep_assert_held_once(&up->port.lock);
+
 	__serial8250_clear_IER(up);
 }