refactor(vmm): Remove unnecessary pub visibility

Remove `pub` from `HYPERVISOR_BITINDEX` since it is not unsed outside
`update_feature_info_entry()`.

Signed-off-by: Takahiro Itazuri <[email protected]>

Author: zulinx86

src/vmm/src/cpu_config/x86_64/cpuid/normalize.rs

@@ -213,7 +213,7 @@ impl super::Cpuid {
         const TSC_DEADLINE_BITINDEX: u8 = 24;
 
         /// CPU is running on a hypervisor.
-        pub const HYPERVISOR_BITINDEX: u8 = 31;
+        const HYPERVISOR_BITINDEX: u8 = 31;
 
         let leaf_1 = self
             .get_mut(&CpuidKey::leaf(0x1))