wl12xx: configure rate policy for p2p operations

p2p packets should go out only with OFDM rates.

Configure a new rate policy that will (later) be used
during p2p_find (when the p2p_cli / p2p_go interfaces
are in use, we won't have to use this policy, as
the configured rates should already be OFDM-only).

Additionally, update CONF_TX_MAX_RATE_CLASSES to reflect
the current value from the fw api.

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
diff --git a/drivers/net/wireless/wl12xx/acx.h b/drivers/net/wireless/wl12xx/acx.h
index 556ee4e..e3f93b4 100644
--- a/drivers/net/wireless/wl12xx/acx.h
+++ b/drivers/net/wireless/wl12xx/acx.h
@@ -656,6 +656,7 @@
 
 #define ACX_TX_BASIC_RATE      0
 #define ACX_TX_AP_FULL_RATE    1
+#define ACX_TX_BASIC_RATE_P2P  2
 #define ACX_TX_AP_MODE_MGMT_RATE 4
 #define ACX_TX_AP_MODE_BCST_RATE 5
 struct acx_rate_policy {