virtio-devices: Rename control parameter for VIRTIO_F_ACCESS_PLATFORM

Rename from iommu to access_platform_enabled. The original name was
iommu as this feature was exposed for devices behind an IOMMU however
this feature is also now used for confidential VMs so adopt a more
general name.

Signed-off-by: Rob Bradford <rbradford@meta.com>

virtio-devices/src/rng.rs

@@ -169,7 +169,7 @@ impl Rng {
     pub fn new(
         id: String,
         path: &str,
-        iommu: bool,
+        access_platform_enabled: bool,
         seccomp_action: SeccompAction,
         exit_evt: EventFd,
         state: Option<RngState>,
@@ -182,7 +182,7 @@ impl Rng {
         } else {
             let mut avail_features = 1u64 << VIRTIO_F_VERSION_1;
 
-            if iommu {
+            if access_platform_enabled {
                 avail_features |= 1u64 << VIRTIO_F_ACCESS_PLATFORM;
             }