rt2x00: Add RFKILL support to rt2500usb and rt73usb

Some very rare Ralink USB hardware exists which features
the RFKILL switch on the USB stick.
This patch adds the EEPROM check function to see if RFKILL
is supported and the polling function to rt2500usb and
rt73usb in order to support RFKILL for that hardware.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2500usb.h b/drivers/net/wireless/rt2x00/rt2500usb.h
index 4347dfd..e1f714e 100644
--- a/drivers/net/wireless/rt2x00/rt2500usb.h
+++ b/drivers/net/wireless/rt2x00/rt2500usb.h
@@ -189,6 +189,14 @@
  * MAC_CSR19: GPIO control register.
  */
 #define MAC_CSR19			0x0426
+#define MAC_CSR19_BIT0			FIELD32(0x0001)
+#define MAC_CSR19_BIT1			FIELD32(0x0002)
+#define MAC_CSR19_BIT2			FIELD32(0x0004)
+#define MAC_CSR19_BIT3			FIELD32(0x0008)
+#define MAC_CSR19_BIT4			FIELD32(0x0010)
+#define MAC_CSR19_BIT5			FIELD32(0x0020)
+#define MAC_CSR19_BIT6			FIELD32(0x0040)
+#define MAC_CSR19_BIT7			FIELD32(0x0080)
 
 /*
  * MAC_CSR20: LED control register.