serial: 8250_pericom: Re-enable higher baud rates

Add UPF_MAGIC_MULTIPLIER to the port flags since there is now
range checking in serial8250_get_baud_rate() in 8250_port.c.

Signed-off-by: Jay Dolan <jay.dolan@accesio.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211122133512.8947-3-andriy.shevchenko@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>