wl1271: use the correct macro when setting the basic rates

We were using CONF_TX_RATE_MASK_ALL when calling wl1271_acx_rate_policies()
during init.  We should use WL1271_DEFAULT_BASIC_RATE_SET instead.  The
values are the same, but the latter is just the correct macro to use.

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>