rt2x00: rt2800lib: fix default VGC values for RT3593

Update the rt2800_get_default_vgc function to use the same VGC
values that the DPO_RT5572_LinuxSTA_2.6.1.3_20121022 reference
driver uses.

References:
  RT35xx_ChipAGCAdjust in chips/rt35xx.c
  RT3593_R66_MID_LOW_SENS_GET macro in include/chip/rt3593.h
  RT3593_R66_NON_MID_LOW_SEMS_GET macro in include/chips/rt3593.h

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Acked-by: Stanislaw Gruszka <stf_xl@wp.pl>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2800lib.c

@@ -4413,6 +4413,7 @@ static u8 rt2800_get_default_vgc(struct rt2x00_dev *rt2x00dev)
 		    rt2x00_rt(rt2x00dev, RT3290) ||
 		    rt2x00_rt(rt2x00dev, RT3390) ||
 		    rt2x00_rt(rt2x00dev, RT3572) ||
+		    rt2x00_rt(rt2x00dev, RT3593) ||
 		    rt2x00_rt(rt2x00dev, RT5390) ||
 		    rt2x00_rt(rt2x00dev, RT5392) ||
 		    rt2x00_rt(rt2x00dev, RT5592))
@@ -4422,6 +4423,8 @@ static u8 rt2800_get_default_vgc(struct rt2x00_dev *rt2x00dev)
 	} else { /* 5GHZ band */
 		if (rt2x00_rt(rt2x00dev, RT3572))
 			vgc = 0x22 + (rt2x00dev->lna_gain * 5) / 3;
+		else if (rt2x00_rt(rt2x00dev, RT3593))
+			vgc = 0x20 + (rt2x00dev->lna_gain * 5) / 3;
 		else if (rt2x00_rt(rt2x00dev, RT5592))
 			vgc = 0x24 + (2 * rt2x00dev->lna_gain);
 		else {