[SERIAL] OMAP1510 serial fix for 115200 baud

The patch below is necessary for 115200 baud on an OMAP1510 internal UART.
It's been in the linux-omap tree for some time and with it applied to a
vanilla Linus git tree the serial console on the Amstrad Delta (which is
OMAP1510 based and whose initial bootloader runs at 115200) works fine (it
doesn't without it).

Signed-off-by: Jonathan McDowell <noodles@earth.li>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>