serial: 8250_fsl: fix handle_irq locking

serial: 8250_fsl: fix handle_irq locking

The 8250 handle_irq callback is not just called from the interrupt
handler but also from a timer callback when polling (e.g. for ports
without an interrupt line). Consequently the callback must explicitly
disable interrupts to avoid a potential deadlock with another interrupt
in polled mode.

Fix up the two paths in the freescale callback that failed to re-enable
interrupts when polling.

Fixes: 853a9ae29e97 ("serial: 8250: fix handle_irq locking")
Cc: stable@vger.kernel.org	# 5.13
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/Y/xYzqp4ogmOF5t0@kili
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230227085046.24282-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>