AR9003's PAPRD was enabled prematurely, and is causing some
large discrepancies on throughput and network connectivity.
For example downlink (RX) throughput against an AR9280 AP
can vary widlely from 43-73 Mbit/s while disabling this
gets AR9382 (2x2) up to around 93 Mbit/s in a 2.4 GHz HT20 setup.

Cc: stable@kernel.org
Cc: Paul Shaw <paul.shaw@atheros.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>