adapter: Deprecate Amontec JTAG Accelerator driver

The adapter is not available for years now and Amontec is not even a
company anymore. The poor hardware availability and the lack of users
prevents testing, maintenance and adaptations to future changes.

Mark the adapter as deprecated as a first step to give potential users
the opportunity to upgrade the hardware until the next OpenOCD release.

Change-Id: Idd9fb75588246bc39e12ea17a71435ed77f0f50b
Signed-off-by: Marc Schink <dev@zapb.de>
Reviewed-on: https://review.openocd.org/c/openocd/+/8349
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Tested-by: jenkins

configure.ac

@@ -857,6 +857,12 @@ AS_IF([test "x$use_internal_jimtcl" = "xyes"], [
   AC_MSG_WARN([Using the internal jimtcl is deprecated and will not be possible in the future.])
 ])
 
+AS_IF([test "x$enable_amtjtagaccel" != "xno"], [
+  echo
+  echo
+  AC_MSG_WARN([Amontec JTAG-Accelerator adapter is deprecated and support will be removed in the next release!])
+])
+
 echo
 echo
 echo OpenOCD configuration summary

doc/openocd.texi

@@ -2508,6 +2508,8 @@ enabled when OpenOCD is configured, in order to be made
 available at run time.
 
 @deffn {Interface Driver} {amt_jtagaccel}
+@b{Note: This adapter is deprecated and support will be removed in the next release!}
+
 Amontec Chameleon in its JTAG Accelerator configuration,
 connected to a PC's EPP mode parallel port.
 This defines some driver-specific commands:

src/jtag/drivers/amt_jtagaccel.c

@@ -419,6 +419,8 @@ static int amt_jtagaccel_init(void)
 #endif
 	uint8_t ar_status;
 
+	LOG_WARNING("This adapter is deprecated and support will be removed in the next release!");
+
 #if PARPORT_USE_PPDEV == 1
 	if (device_handle > 0) {
 		LOG_ERROR("device is already opened");