vmbase: Move dbm to aarch64

Moving management of Dirty pages to aarch64 director as a preparation for adding new CPU Architecture.

Bug: 362733888
Test: m libvmbase

Change-Id: Id8660e8d42229970785d4374b6f55819489961ec
diff --git a/libs/libvmbase/src/arch/aarch64.rs b/libs/libvmbase/src/arch/aarch64.rs
index 2933386..a3f1dd5 100644
--- a/libs/libvmbase/src/arch/aarch64.rs
+++ b/libs/libvmbase/src/arch/aarch64.rs
@@ -14,6 +14,7 @@
 
 //! Wrappers of assembly calls.
 
+pub mod dbm;
 pub mod layout;
 pub mod linker;
 pub mod page_table;