ath9k_hw: Fix STA connection issues with AR9380 (XB113).

commit be0e6aa5a0c487a2a0880dda8bc70f7f1860fc39 upstream.

XB113 (AR9380) 3x3 SB 5G only cards were failing to connect to APs
due to incorrect xpabiaslevel configuration. fix it.

Cc: Ray Li <ray.li@greenwavereality.com>
Cc: Kathy Giori <kathy.giori@atheros.com>
Cc: Aeolus Yang <aeolus.yang@atheros.com>
Cc: compat@orbit-lab.org
Signed-off-by: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>