wifi: rtl8xxxu: Fix HT40 channel config for RTL8192CU, RTL8723AU

wifi: rtl8xxxu: Fix HT40 channel config for RTL8192CU, RTL8723AU

Flip the response rate subchannel. It was backwards, causing low
speeds when using 40 MHz channel width. "iw dev ... station dump"
showed a low RX rate, 11M or less.

Also fix the channel width field of RF6052_REG_MODE_AG.

Tested only with RTL8192CU, but these settings are identical for
RTL8723AU.

Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/1f46571d-855b-43e1-8bfc-abacceb96043@gmail.com