Remove ctrl_rate, cw40index, sgi_index, ht_index and calculate
the rate index for TX status from the valid_rate_index that
is populated at initialization time.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>