src: Add compile time check for SNP and TDX

We need to make sure that SEV-SNP and TDX are not enabled at the same
time. As these two features belong to mutually exclusive hardware
vendors. So, we should make sure that these two features are not enabled
at the same. Thus, a compile time check for it.

Signed-off-by: Jinank Jain <jinankjain@microsoft.com>

src/main.rs

@@ -662,6 +662,9 @@ fn start_vmm(toplevel: TopLevel) -> Result<Option<String>, Error> {
 }
 
 fn main() {
+    #[cfg(all(feature = "tdx", feature = "sev_snp"))]
+    compile_error!("Feature 'tdx' and 'sev_snp' are mutually exclusive.");
+
     #[cfg(feature = "dhat-heap")]
     let _profiler = dhat::Profiler::new_heap();