of/spi: Fix OF-style driver binding of spi devices

This patch adds the OF hook to the spi core so that devices
can automatically be registered based on device tree data.  This fixes
a problem with spi devices not binding to drivers after the cleanup of
the spi & i2c binding code.

Signed-off-by: Sinan Akman <sinan@writeme.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

drivers/spi/spi.c

@@ -23,6 +23,7 @@
 #include <linux/init.h>
 #include <linux/cache.h>
 #include <linux/mutex.h>
+#include <linux/of_device.h>
 #include <linux/slab.h>
 #include <linux/mod_devicetable.h>
 #include <linux/spi/spi.h>
@@ -86,6 +87,10 @@ static int spi_match_device(struct device *dev, struct device_driver *drv)
 	const struct spi_device	*spi = to_spi_device(dev);
 	const struct spi_driver	*sdrv = to_spi_driver(drv);
 
+	/* Attempt an OF style match */
+	if (of_driver_match_device(dev, drv))
+		return 1;
+
 	if (sdrv->id_table)
 		return !!spi_match_id(sdrv->id_table, spi);