hypervisor: enable TSC cpuid leaf synthesis for haxm.

Similar to WHPX, haxm requires an accurate (calibrated) leaf value to
make the guest clocksource work accurately.

BUG=b:213152505
TEST=battle tested downstream

Change-Id: I55a45c00758b2112aced6185970ad43df060d0ba
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3731287
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Noah Gold <nkgold@google.com>
Reviewed-by: Vikram Auradkar <auradkar@google.com>
Reviewed-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
Reviewed-by: Alexandre Courbot <acourbot@chromium.org>

hypervisor/src/haxm/vm.rs

@@ -182,8 +182,13 @@ impl Vm for HaxmVm {
         })
     }
 
-    fn check_capability(&self, _c: VmCap) -> bool {
-        false
+    fn check_capability(&self, c: VmCap) -> bool {
+        match c {
+            // under haxm, guests rely on this leaf to calibrate their
+            // clocksource.
+            VmCap::CalibratedTscLeafRequired => true,
+            _ => false,
+        }
     }
 
     fn get_memory(&self) -> &GuestMemory {