hypervisor: Add control for dirty page logging

When creating a userspace mapping provide a control for enabling the
logging of dirty pages.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

hypervisor/src/vm.rs

@@ -189,6 +189,7 @@ pub trait Vm: Send + Sync {
         memory_size: u64,
         userspace_addr: u64,
         readonly: bool,
+        log_dirty_pages: bool,
     ) -> MemoryRegion;
     /// Creates/modifies a guest physical memory slot.
     fn set_user_memory_region(&self, user_memory_region: MemoryRegion) -> Result<()>;