hw: Remove PCMCIA subsystem

hw: Remove PCMCIA subsystem

The only PCMCIA subsystem was the PXA2xx SoC and the machines
using it, which have now been removed. Although in theory
we have a few machine types which have PCMCIA (e.g. kzm,
the strongarm machines, sh4's sh7750), none of those machines
implement their PCMCIA controller, and they're all old and
no longer very interesting machine types.

Rather than keeping all the PCMCIA code in-tree without any
active users of it, delete it. If we need PCMCIA in future
we can always resurrect it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241003140010.1653808-5-peter.maydell@linaro.org