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>

tcl/board/easydevkits/esp32-wrover-e-ftdi-jtag-devkit.cfg

@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Example OpenOCD configuration file for the EasyDevKits ESP32-WROVER-E FTDI JTAG DevKit.
+#
+# For example, OpenOCD can be started for ESP32 debugging on
+#
+#   openocd -f board/esp32-wrover-e-ftdi-jtag-devkit.cfg
+#
+
+# Select the FTDI JTAG driver
+adapter driver ftdi
+
+# Identify the device
+ftdi device_desc "EasyDevKit"
+ftdi vid_pid 0x0403 0x6010
+# interface 0 is JTAG; interface 1 is the uart
+ftdi channel 0
+
+# TCK, TDI, TDO, TMS: ADBUS0-3
+# activity LED: ADBUS4
+ftdi layout_init 0x0008 0x001b
+ftdi layout_signal LED -data 0x0010
+
+# Source the ESP32 configuration file
+source [find target/esp32.cfg]
+
+# ---------------------------------------------------------------------------
+# JTAG speed (in kHz)
+#
+# If you encounter DSR/DIR errors that are not caused by OpenOCD
+# attempting to read unmapped memory regions, try lowering this value.
+#
+# Recommended settings for EasyDevKits:
+#   - Do not exceed 20 MHz.
+#   - Best results are typically achieved at 20 MHz.
+# ---------------------------------------------------------------------------
+adapter speed 20000

tcl/board/easydevkits/esp32-wrover-e-wch-jtag-devkit.cfg

@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Example OpenOCD configuration file for the EasyDevKits ESP32-WROVER-E WCH JTAG DevKit.
+#
+# For example, OpenOCD can be started for ESP32 debugging on
+#
+#   openocd -f board/esp32-wrover-e-wch-jtag-devkit.cfg
+#
+
+# Select the CH347 JTAG driver
+adapter driver ch347
+
+# Identify the device
+ch347 device_desc "EasyDevKit"
+ch347 vid_pid 0x1a86 0x55dd
+
+# Configure activity LED
+# Note: The LED is active-low on GPIO4.
+adapter gpio led 4 -active-low
+
+# Source the ESP32 configuration file
+source [find target/esp32.cfg]
+
+# ---------------------------------------------------------------------------
+# JTAG speed (in kHz)
+#
+# If you encounter DSR/DIR errors that are not caused by OpenOCD
+# attempting to read unmapped memory regions, try lowering this value.
+#
+# Recommended settings for EasyDevKits:
+#   - Do not exceed 30 MHz.
+#   - Best results are typically achieved at 15 MHz.
+#
+# Supported frequencies (kHz):
+#   469, 938, 1875, 3750, 7500, 15000, 30000, 60000
+# ---------------------------------------------------------------------------
+adapter speed 15000