aspeed: Deprecate the tacoma-bmc machine

The tacoma-bmc machine was a board including an AST2600 SoC based BMC
and a witherspoon like OpenPOWER system. It was used for bring up of
the AST2600 SoC in labs. It can be easily replaced by the rainier-bmc
machine which is part of a real product offering.

Signed-off-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

docs/about/deprecated.rst

@@ -256,6 +256,14 @@ images are not available, OpenWRT dropped support in 2019, U-Boot in
 2017, Linux also is dropping support in 2024. It is time to let go of
 this ancient hardware and focus on newer CPUs and platforms.
 
+Arm ``tacoma-bmc`` machine (since 9.1)
+''''''''''''''''''''''''''''''''''''''''
+
+The ``tacoma-bmc`` machine was a board including an AST2600 SoC based
+BMC and a witherspoon like OpenPOWER system. It was used for bring up
+of the AST2600 SoC in labs.  It can be easily replaced by the
+``rainier-bmc`` machine which is a real product.
+
 Backend options
 ---------------
 

hw/arm/aspeed.c

@@ -1379,6 +1379,8 @@ static void aspeed_machine_tacoma_class_init(ObjectClass *oc, void *data)
     amc->i2c_init  = witherspoon_bmc_i2c_init; /* Same board layout */
     mc->default_ram_size = 1 * GiB;
     aspeed_machine_class_init_cpus_defaults(mc);
+
+    mc->deprecation_reason = "Please use the similar 'rainier-bmc' machine";
 };
 
 static void aspeed_machine_g220a_class_init(ObjectClass *oc, void *data)