build: Fix beta clippy issue (derive_partial_eq_without_eq)

warning: you are deriving `PartialEq` and can implement `Eq`
  --> vmm/src/serial_manager.rs:59:30
   |
59 | #[derive(Debug, Clone, Copy, PartialEq)]
   |                              ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#derive_partial_eq_without_eq

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

arch/src/lib.rs

@@ -54,7 +54,7 @@ pub enum Error {
 pub type Result<T> = result::Result<T, Error>;
 
 /// Type for memory region types.
-#[derive(Clone, Copy, PartialEq, Debug, Serialize, Deserialize, Versionize)]
+#[derive(Clone, Copy, PartialEq, Eq, Debug, Serialize, Deserialize, Versionize)]
 pub enum RegionType {
     /// RAM type
     Ram,