ath9k: Fix suspend/resume when no interface is UP

When no interface has been brought up, the chip's power
state continued as AWAKE. So during resume, the chip never
been powered up.

Cc: stable@kernel.org
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>