cmd: abootimg: Add 'get ramdisk' command

cmd: abootimg: Add 'get ramdisk' command

Add support for retrieving ramdisk address and size from Android boot
images. This command allows users to extract the ramdisk information
for boot image v3+ which combines vendor ramdisk, boot ramdisk and
bootconfig sections.

Reviewed-by: Mattijs Korpershoek <mkorpershoek@kernel.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Guillaume La Roque (TI.com) <glaroque@baylibre.com>
Link: https://lore.kernel.org/r/20260112-bootconfig-v5-4-79b242159ac7@baylibre.com
Signed-off-by: Mattijs Korpershoek <mkorpershoek@kernel.org>