ath9k_hw: remove AR9485 1.0 support

Only AR9485 1.1 was sold. This debloats the driver by ~14 KiB.

   text    data     bss     dec     hex filename
 300413     624    1056  302093   49c0d drivers/net/wireless/ath/ath9k/ath9k_hw.ko

   text    data     bss     dec     hex filename
 310285     624    1056  311965   4c29d drivers/net/wireless/ath/ath9k/ath9k_hw-old.ko

$ du -b ath9k_hw*
6210541	ath9k_hw.ko
6225089	ath9k_hw-old.ko

Cc: Bill Wu <bill.wu@atheros.com>
Cc: Paul Shaw <paul.shaw@atheros.com>
Cc: Forbes Tsai <Forbes.Tsai@Atheros.com>
Cc: Jesmine Chen <jesmine.chen@atheros.com>
Cc: Marvian Chen <Hou-hua.Chen@Atheros.com>
Cc: Vivek Natarajan <vivek.natarajan@atheros.com>
Cc: Bernadette Yetso <bernadette.yetso@atheros.com>
Cc: Sarvesh Shrivastava <sarvesh.shrivastava@atheros.com>
Acked-by: Yi-Chen Su <yi-chen.su@atheros.com>
Acked-by: Jeffrey Chung <jeffrey.chung@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>