rt2800: comment and simplify AGC init for RT6352

We do not need separate lines for calculating register values.
Also add comment that value is different than in vendor driver.
Suggested-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ralink/rt2x00/rt2800lib.c

@@ -3989,9 +3989,12 @@ static void rt2800_config_channel(struct rt2x00_dev *rt2x00dev,
 		rt2800_bbp_write(rt2x00dev, 195, 141);
 		rt2800_bbp_write(rt2x00dev, 196, reg);
 
-		/* AGC init */
-		reg = rf->channel <= 14 ? 0x1c : 0x24;
-		reg += 2 * rt2x00dev->lna_gain;
+		/* AGC init.
+		 * Despite the vendor driver using different values here for
+		 * RT6352 chip, we use 0x1c for now. This may have to be changed
+		 * once TSSI got implemented.
+		 */
+		reg = (rf->channel <= 14 ? 0x1c : 0x24) + 2*rt2x00dev->lna_gain;
 		rt2800_bbp_write_with_rx_chain(rt2x00dev, 66, reg);
 
 		rt2800_iq_calibrate(rt2x00dev, rf->channel);