tcl/board: Support for Digilent Anvyl board

Support Digilent Anvyl board JTAG chain

Change-Id: I6fb52284429af6c98c19411fc8bc3ab983dfa9b8
Signed-off-by: Adam Novak <interfect@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/8467
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

tcl/board/digilent_anvyl.cfg

@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Digilent Anvyl with Xilinx Spartan-6 FPGA
+# https://digilent.com/reference/programmable-logic/anvyl/start
+# Almost the same setup as the Digilent Nexys Video board or the Digilent HS1
+# adapter.
+adapter driver ftdi
+adapter speed 30000
+
+ftdi device_desc "Digilent USB Device"
+ftdi vid_pid 0x0403 0x6010
+
+# channel 0 is the JTAG channel
+# channel 1 is a user serial channel to pins on the FPGA
+ftdi channel 0
+
+# just TCK TDI TDO TMS, no reset
+ftdi layout_init 0x0088 0x008b
+reset_config none
+
+# Enable sampling on falling edge for high JTAG speeds.
+ftdi tdo_sample_edge falling
+
+transport select jtag
+
+source [find cpld/xilinx-xc6s.cfg]
+source [find cpld/jtagspi.cfg]