Do not use bare-metal v0.2.5 (changes MSRV)

Cargo.toml

@@ -9,7 +9,7 @@ keywords = ["riscv", "register", "peripheral"]
 license = "ISC"
 
 [dependencies]
-bare-metal = "0.2.0"
+bare-metal = ">=0.2.0,<0.2.5"
 bit_field = "0.9.0"
 
 [features]