Allocate BARs for all VirtIO PCI devices.

Bug: 237249346
Test: Ran pVM firmware manually.
Change-Id: I5bf4707b9f9edb020b96fa3db740c24a4c4b789b
diff --git a/pvmfw/src/entry.rs b/pvmfw/src/entry.rs
index d307759..2763e80 100644
--- a/pvmfw/src/entry.rs
+++ b/pvmfw/src/entry.rs
@@ -48,6 +48,8 @@
     InvalidRamdisk,
     /// Failed to verify the payload.
     PayloadVerificationError,
+    /// Error interacting with a VirtIO PCI device.
+    PciError,
 }
 
 main!(start);