Defer AML initialization until PCI registration completes.

When acpid starts before pcid has registered the PCI fd, AML
initialization fails with a misleading ERROR-level message. This is
expected on every boot because the service ordering requires acpid to
start before pcid-spawner. The AML interpreter initializes successfully
after pcid registers via /scheme/acpi/register_pci.

Changes:
- aml_context_mut(): log at DEBUG instead of ERROR when PCI fd is None
  (expected pre-registration state, not a fault)
- Fadt::init(): skip \\_S5 evaluation when PCI is not yet registered,
  since refresh_s5_values() is retried in register_pci_fd() after PCI
  registration completes

diff -urN a/drivers/acpid/src/acpi.rs b/drivers/acpid/src/acpi.rs
--- a/drivers/acpid/src/acpi.rs
+++ b/drivers/acpid/src/acpi.rs
@@ -896,7 +896,11 @@
             match self.init(pci_fd) {
                 Ok(()) => (),
                 Err(err) => {
-                    log::error!("failed to initialize AML context: {}", err);
+                    if pci_fd.is_none() {
+                        log::debug!("AML init deferred until PCI registration: {}", err);
+                    } else {
+                        log::error!("failed to initialize AML context: {}", err);
+                    }
                 }
             }
         }
@@ -2004,8 +2008,12 @@
 
         context.tables.push(dsdt_sdt);
 
-        if let Err(error) = context.refresh_s5_values() {
-            log::warn!("Failed to evaluate \\_S5 during FADT init: {error}");
+        if context.pci_ready() {
+            if let Err(error) = context.refresh_s5_values() {
+                log::warn!("Failed to evaluate \\_S5 during FADT init: {error}");
+            }
+        } else {
+            log::debug!("Deferring \\_S5 evaluation until PCI registration");
         }
     }
 }