wl1271: limit TX power to 25dBm for every channel

The wl1271 firmware supports maximun 25.5dBm, so the driver was returning
-EINVALID to anything above that.  This patch uses the channel max_power
option to limit the TX power to 25dBm.
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>

drivers/net/wireless/wl12xx/wl1271_main.c

@@ -1675,19 +1675,19 @@ static struct ieee80211_rate wl1271_rates[] = {
 
 /* can't be const, mac80211 writes to this */
 static struct ieee80211_channel wl1271_channels[] = {
-	{ .hw_value = 1, .center_freq = 2412},
-	{ .hw_value = 2, .center_freq = 2417},
-	{ .hw_value = 3, .center_freq = 2422},
-	{ .hw_value = 4, .center_freq = 2427},
-	{ .hw_value = 5, .center_freq = 2432},
-	{ .hw_value = 6, .center_freq = 2437},
-	{ .hw_value = 7, .center_freq = 2442},
-	{ .hw_value = 8, .center_freq = 2447},
-	{ .hw_value = 9, .center_freq = 2452},
-	{ .hw_value = 10, .center_freq = 2457},
-	{ .hw_value = 11, .center_freq = 2462},
-	{ .hw_value = 12, .center_freq = 2467},
-	{ .hw_value = 13, .center_freq = 2472},
+	{ .hw_value = 1, .center_freq = 2412, .max_power = 25 },
+	{ .hw_value = 2, .center_freq = 2417, .max_power = 25 },
+	{ .hw_value = 3, .center_freq = 2422, .max_power = 25 },
+	{ .hw_value = 4, .center_freq = 2427, .max_power = 25 },
+	{ .hw_value = 5, .center_freq = 2432, .max_power = 25 },
+	{ .hw_value = 6, .center_freq = 2437, .max_power = 25 },
+	{ .hw_value = 7, .center_freq = 2442, .max_power = 25 },
+	{ .hw_value = 8, .center_freq = 2447, .max_power = 25 },
+	{ .hw_value = 9, .center_freq = 2452, .max_power = 25 },
+	{ .hw_value = 10, .center_freq = 2457, .max_power = 25 },
+	{ .hw_value = 11, .center_freq = 2462, .max_power = 25 },
+	{ .hw_value = 12, .center_freq = 2467, .max_power = 25 },
+	{ .hw_value = 13, .center_freq = 2472, .max_power = 25 },
 };
 
 /* can't be const, mac80211 writes to this */