spi: omap-uwire: add missing iounmap

This fixes the following coccicheck warning:
linux-2.6/drivers/spi/spi-omap-uwire.c:485:2-8: ERROR: missing iounmap; ioremap on line 471 and execution via conditional on line 481

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
1 file changed