rt2x00: Fix max TX power settings

During initialization each driver reads the default TX power
for each individual channel. However mac80211 only accepts the
maximum value (which is also handled as default value).

As a result, the TX power of the device was being limited to
the default value, which is often quite low compared to the
real maximum acceptable value.

This patch allows each driver to set the maximum value on a
per-channel basis which is forwarded to mac80211. The default
value will be preserved for now, in case we want to update
mac80211 to differentiate between the maximum and default txpower.

This fixes bug complaining about limited TX power values like:
https://bugzilla.kernel.org/show_bug.cgi?id=16358

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Acked-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2800.h b/drivers/net/wireless/rt2x00/rt2800.h
index cf1f16b..5c006a7 100644
--- a/drivers/net/wireless/rt2x00/rt2800.h
+++ b/drivers/net/wireless/rt2x00/rt2800.h
@@ -1859,6 +1859,13 @@
 #define EEPROM_RSSI_A2_LNA_A2		FIELD16(0xff00)
 
 /*
+ * EEPROM Maximum TX power values
+ */
+#define EEPROM_MAX_TX_POWER		0x0027
+#define EEPROM_MAX_TX_POWER_24GHZ	FIELD16(0x00ff)
+#define EEPROM_MAX_TX_POWER_5GHZ	FIELD16(0xff00)
+
+/*
  * EEPROM TXpower delta: 20MHZ AND 40 MHZ use different power.
  *	This is delta in 40MHZ.
  * VALUE: Tx Power dalta value (MAX=4)