Use git version.

riscv-rt/Cargo.toml

@@ -10,4 +10,6 @@ license = "ISC"
 
 [dependencies]
 r0 = "^0.2.1"
-riscv = "^0.1.3"
+
+[dependencies.riscv]
+git = "https://github.com/dvc94ch/riscv"