[macros] Remove riscv-rt dependency

riscv-rt/macros/Cargo.toml

@@ -26,6 +26,3 @@ version = "0.15.13"
 [dependencies.rand]
 version = "0.5.5"
 default-features = false
-
-[dev-dependencies]
-riscv-rt = { path = "..", version = "0.5.0" }