tty: serial: 8250: Set RS232 as default for Moxa PCIe board initialization

tty: serial: 8250: Set RS232 as default for Moxa PCIe board initialization

After switching the serial interface of the Moxa RS232 PCIe boards, it
fails to reset to RS232 when attempting to reload 8250_pci driver.

This patch set RS232 as the default setting during the initialization of
Moxa PCIe board.

Signed-off-by: Crescent CY Hsieh <crescentcy.hsieh@moxa.com>
Link: https://lore.kernel.org/r/20240102053133.9795-1-crescentcy.hsieh@moxa.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>