runtime-rs: Enable initdata spec for IBM SEL

Add support for the `InitData` resource config on IBM SEL,
so that a corresponding block device is created and the
initdata is passed to the guest through this device.

Note that we skip passing the initdata hash via QEMU’s
object, since the hypervisor does not yet support this
mechanism for IBM SEL. It will be introduced separately
once QEMU adds the feature.

Signed-off-by: Hyounggyu Choi <Hyounggyu.Choi@ibm.com>

src/runtime-rs/crates/runtimes/virt_container/src/sandbox.rs

@@ -452,6 +452,7 @@ impl VirtSandbox {
             GuestProtection::Snp(_details) => {
                 calculate_initdata_digest(&initdata, ProtectedPlatform::Snp)?
             }
+            GuestProtection::Se => calculate_initdata_digest(&initdata, ProtectedPlatform::Se)?,
             // TODO: there's more `GuestProtection` types to be supported.
             _ => return Ok(None),
         };