b43: AC-PHY: prepare place for developing new PHY support

There are new (not anymore?) Broadcom 802.11ac wireless cards based on
chipsets like BCM4352 and BCM4360. They use a new PHY type (called
simply AC) that will require new specific code.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/b43/phy_common.h

@@ -222,6 +222,8 @@ struct b43_phy {
 		struct b43_phy_ht *ht;
 		/* LCN-PHY specific information */
 		struct b43_phy_lcn *lcn;
+		/* AC-PHY specific information */
+		struct b43_phy_ac *ac;
 	};
 
 	/* Band support flags. */