wl1271: use channel 1 when configuring the data path

In the data path configuration, one of the parameters is the channel.  We
have been setting it to wl->channel, which is not correct in this case.  This
channel has nothing to do with the channel we're currently tuned to, since it
is only used for calibration during this phase.  Hardcoded the channel to 1,
according to the reference driver.

Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Reviewed-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>