Revert "[Zion][Yellowstone] First pass at adding PCI ioport access."

This reverts commit b677633248.

rust/lib/mammoth/build.rs

@@ -15,11 +15,4 @@ fn main() {
         curr_directory.to_str().unwrap()
     );
     println!("cargo:rustc-link-lib=zion_stub");
-
-    // Trying to recreate bindings?
-    // Run the following commands
-    // gcc -E zion/include/zcall.h > /tmp/expanded.h
-    // bindgen --verbose --use-core --no-layout-tests /tmp/expanded.h -o rust/lib/mammoth/src/bindings.rs -- -x c++
-    //
-    // Then go fix the ThreadExit struct.
 }