hw/cxl/cxl-mailbox-utils: Add dynamic capacity region representative and mailbox...

hw/cxl/cxl-mailbox-utils: Add dynamic capacity region representative and mailbox command support

Per cxl spec r3.1, add dynamic capacity (DC) region representative based on
Table 8-165 and extend the cxl type3 device definition to include DC region
information. Also, based on info in 8.2.9.9.9.1, add 'Get Dynamic Capacity
Configuration' mailbox support.

Note: we store region decode length as byte-wise length on the device, which
should be divided by 256 * MiB before being returned to the host
for "Get Dynamic Capacity Configuration" mailbox command per
specification.

Reviewed-by: Gregory Price <gregory.price@memverge.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Fan Ni <fan.ni@samsung.com>
Message-Id: <20240523174651.1089554-5-nifan.cxl@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>