jtag/ch347: Refine driver and configs for EasyDevKits adapters

This commit improves support for CH347-based JTAG adapters:

- configure.ac: removed "Mode3" restriction (CH347F does not require mode).
- configs: added board config for ESP32-WROVER-E WCH JTAG DevKit and
  ESP32-WROVER-E FTDI JTAG DevKit
- ch347 driver: removed `ch347 activity_led` command; activity LED
  is now controlled via the generic `adapter gpio led` command.
- doc/openocd.texi: updated documentation accordingly.

Change-Id: I5524290297adcc004e00af919181868d2b6303af
Signed-off-by: EasyDevKits <info@easydevkits.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/9015
Reviewed-by: zapb <dev@zapb.de>
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

doc/openocd.texi

@@ -2590,6 +2590,9 @@ mitigates the problem.
 @end itemize
 @end itemize
 
+The driver supports activity LED through the generic
+command @ref{adapter gpio, @command{adapter gpio led}}.
+
 This driver has these driver-specific command:
 
 @deffn {Config Command} {ch347 vid_pid} [vid pid]+
@@ -2609,17 +2612,6 @@ and product ID will be connected.
 ch347 device_desc "EasyDevKit"
 @end example
 @end deffn
-
-@deffn {Config Command} {ch347 activity_led} [n]gpio_number
-If specified the drive let an activity LED blink during JTAG operations.
-The number is the GPIO number of the CH347T chip. If prefixed with "n",
-then this GPIO should be low active. The example configures GPIO4 as
-low active activity LED. For the CH347T chip only GPIO3 (Pin11 / SCL),
-GPIO4 (Pin15 / ACT), GPIO5 (Pin9 / TRST) and GPIO6 (Pin2 / CTS1) are possible.
-@example
-ch347 activity_led n4
-@end example
-@end deffn
 @end deffn
 
 @deffn {Interface Driver} {cmsis-dap}