Add support for <cluster> tags to svd2rust.

Cluster tags result in a struct definition that contains each of the
children of that cluster. The children within a module of a type named
after the cluster.

Author: brandonedens

Cargo.lock

@@ -17,10 +17,10 @@ either = "1.0.3"
 error-chain = "0.10.0"
 inflections = "1.1.0"
 quote = "0.3.15"
-svd-parser = "0.5.2"
+svd-parser = "0.6.0"
 syn = "0.11.9"
 
 [[bin]]
 doc = false
 name = "svd2rust"
-path = "src/main.rs"
+path = "src/main.rs"