accept commands.

This patch works around the problem by using the the TX Download Ready
bit in place of the Command Download Ready Bit while in IEEE PS mode.
TX Download Ready is set in IEEE PS mode.

Signed-off-by: Andrey Yurovsky <andrey@cozybit.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
=&/ž9x