Add bindings for sparc64

Author: glaubitz

sys/src/linux/mod.rs

@@ -2,5 +2,6 @@
 #[cfg_attr(target_arch = "x86_64", path = "x86_64.rs")]
 #[cfg_attr(target_arch = "arm", path = "arm.rs")]
 #[cfg_attr(target_arch = "aarch64", path = "aarch64.rs")]
+#[cfg_attr(target_arch = "sparc64", path = "sparc64.rs")]
 mod unsupported;
 pub use unsupported::*;