ath9k: Add custom parameters for CUS198

CUS198 is a card based on AR9485. There are differences
between the base reference design HB125 and CUS198.
Identify such cards based on the PCI subsystem IDs and
set HW parameters appropriately.

Addresses this bug - https://bugzilla.kernel.org/show_bug.cgi?id=49201

Cc: jkp@iki.fi
Cc: gfmichaud@gmail.com
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/hw.h

@@ -307,6 +307,10 @@ struct ath9k_ops_config {
 	u16 spurchans[AR_EEPROM_MODAL_SPURS][2];
 	u8 max_txtrig_level;
 	u16 ani_poll_interval; /* ANI poll interval in ms */
+
+	/* Platform specific config */
+	u32 xlna_gpio;
+	bool xatten_margin_cfg;
 };
 
 enum ath9k_int {