ath9k: make endian check optional

Turns out it triggers on some AR71xx devices where no swapping should be done.
Enable endian check for the lantiq target.

SVN-Revision: 31084

target/linux/generic/files/include/linux/ath9k_platform.h

@@ -29,6 +29,7 @@ struct ath9k_platform_data {
 	u32 gpio_mask;
 	u32 gpio_val;
 
+	bool endian_check;
 	bool is_clk_25mhz;
 	int (*get_mac_revision)(void);
 	int (*external_reset)(void);