wl1251: split spi interface into separate module

This creates a module called wl1251_spi.ko which contains just the
SPI-specific code.  The core remains in the module wl1251.ko.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/wl12xx/wl1251.h b/drivers/net/wireless/wl12xx/wl1251.h
index df4c06d..ebe2c70 100644
--- a/drivers/net/wireless/wl12xx/wl1251.h
+++ b/drivers/net/wireless/wl12xx/wl1251.h
@@ -291,7 +291,7 @@
 	struct ieee80211_hw *hw;
 	bool mac80211_registered;
 
-	struct spi_device *spi;
+	void *if_priv;
 	const struct wl1251_if_operations *if_ops;
 
 	void (*set_power)(bool enable);