libhypervisor_backends: rename kvm to kvm_aarch64

As a preparation for x86 kvm support, use more precise file name, which
currently is aarch64 specific.

Bug: None
Test: build

Change-Id: Ic484f14e051d24930e6646e9e967e4a42661904a
diff --git a/libs/libhypervisor_backends/src/hypervisor.rs b/libs/libhypervisor_backends/src/hypervisor.rs
index 1b45f38..e228e8c 100644
--- a/libs/libhypervisor_backends/src/hypervisor.rs
+++ b/libs/libhypervisor_backends/src/hypervisor.rs
@@ -17,6 +17,8 @@
 mod common;
 mod geniezone;
 mod gunyah;
+#[cfg(target_arch = "aarch64")]
+#[path = "hypervisor/kvm_aarch64.rs"]
 mod kvm;
 
 use super::{Error, Result};
diff --git a/libs/libhypervisor_backends/src/hypervisor/kvm.rs b/libs/libhypervisor_backends/src/hypervisor/kvm_aarch64.rs
similarity index 100%
rename from libs/libhypervisor_backends/src/hypervisor/kvm.rs
rename to libs/libhypervisor_backends/src/hypervisor/kvm_aarch64.rs