arch: Helper functions for u32 hex (de-) serialization

These helper functions will later be used to (de-) serialize CPUID
leaves and MSR register addresses.

Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de>
On-behalf-of: SAP oliver.anderson@sap.com

arch/Cargo.toml

@@ -27,6 +27,7 @@ vmm-sys-util = { workspace = true, features = ["with-serde"] }
 
 [dev-dependencies]
 proptest = "1.0.0"
+serde_json = { workspace = true }
 
 [target.'cfg(any(target_arch = "aarch64", target_arch = "riscv64"))'.dependencies]
 fdt_parser = { version = "0.1.5", package = "fdt" }