APIv1 AP firmware does not support the RF_TX_POWER command.  It
supports the similar TX_POWER command.
Signed-off-by: NPradeep Nemavat <pnemavat@marvell.com>
Signed-off-by: NNishant Sarmukadam <nishants@marvell.com>
Signed-off-by: NBrian Cavagnolo <brian@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>