ath5k: Identify RF2413 and deal with PHY_SPENDING

* Attach RF2413.

 * Propertly handle different AR5K_PHY_SPENDING settings for each RF
chip by adding a field in ath5k_hw. This way we won't have to check
inside hw_reset (see next patch).

Changes-licensed-under: ISC
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@winlab.rutgers.edu>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath5k/ath5k.h

@@ -966,6 +966,7 @@ struct ath5k_hw {
 	u16			ah_phy_revision;
 	u16			ah_radio_5ghz_revision;
 	u16			ah_radio_2ghz_revision;
+	u32			ah_phy_spending;
 
 	enum ath5k_version	ah_version;
 	enum ath5k_radio	ah_radio;