ath9k_hw: Get AHB clock information from ath9k_platform_data

Add a bool in ath9k_platform_data to pass AHB clock speed information.
Driver needs this to configure PLL on some SOCs.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index 450b642..5a4ba09 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -846,6 +846,8 @@
 
 	/* Enterprise mode cap */
 	u32 ent_mode;
+
+	bool is_clk_25mhz;
 };
 
 struct ath_bus_ops {