ath5k: fixup some merge damage for AR5211 IQ calibration

Resolution of a merge conflict upstream accidentally removed a hunk of
"ath5k: IQ calibration for AR5211 is slightly different", so restore it.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath5k/phy.c

@@ -1388,7 +1388,10 @@ static int ath5k_hw_rf511x_calibrate(struct ath5k_hw *ah,
 	i_coff = (-iq_corr) / i_coffd;
 	i_coff = clamp(i_coff, -32, 31); /* signed 6 bit */
 
-	q_coff = (i_pwr / q_coffd) - 128;
+	if (ah->ah_version == AR5K_AR5211)
+		q_coff = (i_pwr / q_coffd) - 64;
+	else
+		q_coff = (i_pwr / q_coffd) - 128;
 	q_coff = clamp(q_coff, -16, 15); /* signed 5 bit */
 
 	ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_CALIBRATE,