vmbase: Export VirtualAddress from arch

This change switches from using VirtualAddress directly from aarch64_paging
crate but from the same type rexported from crate::arch module. This is
currently a purely cosmetical change now. But once the x86_64 supports
will be brought to life, a different type will be in use and rexporting
will prevent excessive use of `cfg(target_arch = "aarch64")` for
imports.

Bug: 362733888
Test: m libvmbase pvmfw_bin vmbase_example_bios_bin vmbase_example_kernel_bin
Change-Id: I57d5a76457f7c396aee2c6528ebd0bb6c93c08c4
diff --git a/libs/libvmbase/src/arch.rs b/libs/libvmbase/src/arch.rs
index 9e4523e..49978d5 100644
--- a/libs/libvmbase/src/arch.rs
+++ b/libs/libvmbase/src/arch.rs
@@ -32,6 +32,9 @@
 #[cfg(target_arch = "aarch64")]
 pub use aarch64::uart;
 
+#[cfg(target_arch = "aarch64")]
+pub use aarch64_paging::paging::VirtualAddress;
+
 /// Write with well-defined compiled behavior.
 ///
 /// See https://github.com/rust-lang/rust/issues/131894