rt2x00: Disable powersaving for rt61pci and rt2800pci.

We've had many reports of rt61pci failures with powersaving enabled.
Therefore, as a stop-gap measure, disable powersaving of the rt61pci
until we have found a proper solution.
Also disable powersaving on rt2800pci as it most probably will show
the same problem.

Cc: stable@kernel.org
Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>