powerpc: drop HPCD/MPC8610 evaluation platform support

This evaluation platform was essentially a single core 8641 with
integrated graphics/display support - in an effort to reduce chip count
on kiosk and similar applications.

Compared to other evaluation platforms considered for removal in other
recent commits, this platform was relatively rare. Unlike all the other
10+ platforms, I couldn't find any documentation on it - just a link to
downloading the 2007 era BSP in "LTIB" format as was done back then.

With all that in mind, it seems prudent to remove it here in 2023.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
[mpe: Drop stale reference to MPC8610_HPCD in 86xx/Kconfig]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230225201318.3682-4-paul.gortmaker@windriver.com

powerpc: drop HPC-NET/MPC8641D evaluation platform support

There is no denying that this was an interesting platform in its day.
Access to a SMP powerpc platform became a bit more obtainable for folks
in the BSP industry in the 2007 era, thanks to this platform.

Add to that the move to the black Antec case vs. the generic white 2005
era case of the MPC8548CDS or the retro 1950s 1/2 height horizontal case
of the HPC II, and it was pretty interesting to people like myself then.

However, like all the other evaluation platforms, the overall system
was complex out of necessity, as it tried to showcase all possible
features and use-cases. That included an AMP option, where you could run
two bootloaders and two kernels over two serial consoles. Peripheral
sharing got a bit more tricky when you got to the hard disk and similar.

In any case we still have the same circumstance. A relatively rare and
expensive evaluation platform that is now 15+ years old and not out there
in large numbers in the general public. Removal in 2023 just makes sense.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230225201318.3682-3-paul.gortmaker@windriver.com

powerpc: retire sbc8641d board support

The support was for this was added to mainline over 12 years ago, in
v2.6.26 [4e8aae89a35d] just around the ppc --> powerpc migration.

I believe the board was introduced shortly after the sbc8548 board,
making it roughly a 14 year old platform - with the CPU speed and
memory size typical for that era.

I haven't had one of these boards for several years, and availability
was discontinued several years before that.

Given that, there is no point in adding a burden to testing coverage
that builds all possible defconfigs, so it makes sense to remove it.

Of course it will remain in the git history forever, for anyone who
happens to find a functional board and wants to tinker with it.

Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/configs: Rename foo_basic_defconfig to foo_base.config

We have several "defconfigs" that are not actually full defconfigs
they are just a base set of options which are then merged with other
fragments to produce a working defconfig.

The most obvious example is corenet_basic_defconfig which only
contains one symbol CONFIG_CORENET_GENERIC=y. And in fact if you build
it as a "defconfig" that one symbol ends up undefined, because its
prerequisites are missing.

There is also mpc85xx_base_defconfig which doesn't actually enable
CONFIG_PPC_85xx.

To avoid confusion, rename these config fragments to "foo_base.config"
to make it clearer that they are not full defconfigs and are instaed
just fragments that are used to generate real defconfigs.

Reported-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190528081614.26096-1-mpe@ellerman.id.au