ath9k: Fix ath9k prevents CPU to enter C3 states

ath9k: Fix ath9k prevents CPU to enter C3 states

The DMA latency issue is observed only in Intel pinetrail platforms
but in the driver we had a default PM-QOS value of 55. This caused
unnecessary power consumption and battery drain in other platforms.

Remove the pm-qos thing in the driver code and address the throughput
issue in Intel pinetrail platfroms in user space using any one of
the scripts in below links:

http://www.kernel.org/pub/linux/kernel/people/mcgrof/scripts/cpudmalatency.c
http://johannes.sipsolutions.net/files/netlatency.c.txt

More details can be found in the following bugzilla link:

https://bugzilla.kernel.org/show_bug.cgi?id=27532

This reverts the following commits:

	0fa8bb2b61747cf734557593f2fa23c6fa5857af
	b61793a79ca224ee9bb841e946b5b35f75b4705d
	5369b2ef166be31cdd4f94b3daa1a4e3de07d8a8

Signed-off-by: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>