commit 47b34d2e upstream.

Since the commit c1a67b48 ("serial: 8250_pci: replace switch-case by
formula for Intel MID"), the 8250 driver crashes in the byt_set_termios()
function with a divide error. This is caused by the fact that a baud rate of 0
(B0) is not handled properly. Fix it by falling back to B9600 in this case.
Reported-by: "Mendez Salinas, Fernando" <fernando.mendez.salinas@intel.com>
Fixes: c1a67b48 ("serial: 8250_pci: replace switch-case by formula for Intel MID")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>