rt2x00: Introduce concept of driver data in struct rt2x00_dev.

We are getting more and more fields in struct rt2x00_dev that are
specific to one or two of the low-level drivers. Instead of putting
these fields inside the main structure and thus clobbering all low-level
drivers with these fields, introduce the concept of driver data inside
struct rt2x00_dev, whose size is indicated by the low-level driver and
which can be populated by the low-level driver.

Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index b03b22c..b4260bfb6 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -647,6 +647,7 @@
  */
 struct rt2x00_ops {
 	const char *name;
+	const unsigned int drv_data_size;
 	const unsigned int max_sta_intf;
 	const unsigned int max_ap_intf;
 	const unsigned int eeprom_size;
@@ -742,6 +743,11 @@
 	const struct rt2x00_ops *ops;
 
 	/*
+	 * Driver data.
+	 */
+	void *drv_data;
+
+	/*
 	 * IEEE80211 control structure.
 	 */
 	struct ieee80211_hw *hw;