hw/arm/xlnx-versal: bbram: refactor creation

hw/arm/xlnx-versal: bbram: refactor creation

Refactor the BBRAM device creation using the VersalMap structure.

Note that the corresponding FDT node is removed. It does not correspond
to any real node in standard Versal DTBs. No matching drivers exist for
it.

Signed-off-by: Luc Michel <luc.michel@amd.com>
Reviewed-by: Francisco Iglesias <francisco.iglesias@amd.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20250926070806.292065-15-luc.michel@amd.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>