TP-Link TL-WR740N v6 GPIO buttons are not correct

Although the model is no longer supported .... It is necessary to correct the source codes for this model, as the GPIO numbers do not match.

--- target/linux/ar71xx/files/arch/mips/ath79/mach-tl-wr841n-v9_old.c	2020-11-11 21:37:42.652784810 +0600
+++ target/linux/ar71xx/files/arch/mips/ath79mach-tl-wr841n-v9.c	2020-11-09 22:35:40.315725671 +0600
@@ -83,8 +83,8 @@
 #define TL_WR740NV6_GPIO_LED_LAN4	11
 #define TL_WR740NV6_GPIO_LED_WLAN	13
-#define TL_WR740NV6_GPIO_BTN_RESET	12
-#define TL_WR740NV6_GPIO_BTN_WIFI	17
+#define TL_WR740NV6_GPIO_BTN_RESET	0
+#define TL_WR740NV6_GPIO_BTN_WIFI	12
 #define TL_WR841NV9_KEYS_POLL_INTERVAL	20	/* msecs */

"ar71xx" is obsolete, please check "ath79" in master (such details are in devicetree there)

In ath79 tree not config for device TL-WT740N-v6 (only v1-v5). I add needed files (dtc and etc.) and config for this device, but firmware compiled from branch ath79 not stable for QCA9533 dev. WAN conection pull down after 100Mbits trafic on several seconds.