vmbase: Move linker to aarch64

This commit move aarch64 linker definition to arch specific module.

Bug: 362733888
Test: m libvmbase

Change-Id: Ib00cbaa981c948e626d58a0f0d818d4ec1f4ceb3
diff --git a/libs/libvmbase/src/arch/aarch64.rs b/libs/libvmbase/src/arch/aarch64.rs
index 905c518..2933386 100644
--- a/libs/libvmbase/src/arch/aarch64.rs
+++ b/libs/libvmbase/src/arch/aarch64.rs
@@ -15,6 +15,7 @@
 //! Wrappers of assembly calls.
 
 pub mod layout;
+pub mod linker;
 pub mod page_table;
 pub mod platform;