build(deps): Update tock-registers dependency to 0.8 (#46)

Author: berkus

Cargo.toml

@@ -24,4 +24,4 @@ default = ["nightly"]
 nightly = ["tock-registers"]
 
 [dependencies]
-tock-registers = { version = "0.7.x", default-features = false, optional = true } # Use it as interface-only library.
+tock-registers = { version = "0.8", default-features = false, optional = true } # Use it as interface-only library.