target: add Espressif ESP32 basic support

ESP32 is a dual core Xtensa SoC
Not full featured yet. Some of the missing functionality:
-Semihosting
-Flash breakpoints
-Flash loader
-Apptrace
-FreeRTOS

Signed-off-by: Erhan Kurubas <erhan.kurubas@espressif.com>
Change-Id: I76fb184aa38ab9f4e30290c038b5ff8850060750
Reviewed-on: https://review.openocd.org/c/openocd/+/6989
Tested-by: jenkins
Reviewed-by: Ian Thompson <ianst@cadence.com>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

tcl/interface/ftdi/esp32_devkitj_v1.cfg

@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Driver for the FT2232H JTAG chip on the Espressif DevkitJ board
+# (and most other FT2232H and FT232H based boards)
+#
+
+adapter driver ftdi
+ftdi vid_pid 0x0403 0x6010 0x0403 0x6014
+
+# interface 1 is the uart
+ftdi channel 0
+
+# TCK, TDI, TDO, TMS: ADBUS0-3
+# LEDs: ACBUS4-7
+
+ftdi layout_init 0x0008 0xf00b
+ftdi layout_signal LED -data 0x1000
+ftdi layout_signal LED2 -data 0x2000
+ftdi layout_signal LED3 -data 0x4000
+ftdi layout_signal LED4 -data 0x8000
+
+# ESP32 series chips do not have a TRST input, and the SRST line is connected to the EN pin.
+# The target code doesn't handle SRST reset properly yet, so this is commented out:
+# ftdi_layout_signal nSRST -oe 0x0020
+# reset_config srst_only