hw/vmapple/cfg: Introduce vmapple cfg region

hw/vmapple/cfg: Introduce vmapple cfg region

Instead of device tree or other more standardized means, VMApple passes
platform configuration to the first stage boot loader in a binary encoded
format that resides at a dedicated RAM region in physical address space.

This patch models this configuration space as a qdev device which we can
then map at the fixed location in the address space. That way, we can
influence and annotate all configuration fields easily.

Signed-off-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Phil Dennis-Jordan <phil@philjordan.eu>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Tested-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-ID: <20241223221645.29911-12-phil@philjordan.eu>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>