ath9k_hw: Disable Walsh spatial spreading for 2 chains

The Walsh bit is disabled for regulatory consideration.

FCC limit for walsh enable is lower than that for walsh disable. So
disabling walsh bit will not limit tx power/affect tx power even in
cases where we are not FCC limited (most client cards). If the tx
power is not FCC limited, then enabling/disabling walsh bit will
not affect Avg. EVM/overall performance in any visible manner.

Cc: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ar9003_2p2_initvals.h

@@ -636,7 +636,7 @@ static const u32 ar9300_2p2_baseband_postamble[][5] = {
 	{0x00009e44, 0x02321e27, 0x02321e27, 0x02291e27, 0x02291e27},
 	{0x00009e48, 0x5030201a, 0x5030201a, 0x50302012, 0x50302012},
 	{0x00009fc8, 0x0003f000, 0x0003f000, 0x0001a000, 0x0001a000},
-	{0x0000a204, 0x000037c0, 0x000037c4, 0x000037c4, 0x000037c0},
+	{0x0000a204, 0x000036c0, 0x000036c4, 0x000036c4, 0x000036c0},
 	{0x0000a208, 0x00000104, 0x00000104, 0x00000004, 0x00000004},
 	{0x0000a22c, 0x01026a2f, 0x01026a2f, 0x01026a2f, 0x01026a2f},
 	{0x0000a230, 0x0000000a, 0x00000014, 0x00000016, 0x0000000b},

drivers/net/wireless/ath/ath9k/ar9003_phy.c

@@ -482,7 +482,7 @@ static void ar9003_hw_set_channel_regs(struct ath_hw *ah,
 		(REG_READ(ah, AR_PHY_GEN_CTRL) & AR_PHY_GC_ENABLE_DAC_FIFO);
 
 	/* Enable 11n HT, 20 MHz */
-	phymode = AR_PHY_GC_HT_EN | AR_PHY_GC_SINGLE_HT_LTF1 | AR_PHY_GC_WALSH |
+	phymode = AR_PHY_GC_HT_EN | AR_PHY_GC_SINGLE_HT_LTF1 |
 		  AR_PHY_GC_SHORT_GI_40 | enableDacFifo;
 
 	/* Configure baseband for dynamic 20/40 operation */