[SERIAL] serial_cs: Add quirk for brainboxes 2-port RS232 card

Mauro Ziliani reports that this card has a higher clock rate.
Rather than tweak the 8250 driver to handle this, add a quirk to
pass the correct clock rate to the driver.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
1 file changed