Move hidl hash into its own lib.

This is required to make it simple for VTS tests to make use of this
library.

Note: also moved host only libs to be host only in the build system

Test: adding things to frozen interfaces breaks the build
Test: hidl-gen compiles android.hardware.nfc@1.0 hal
Bug: 34178341
Merged-In: I763c7ed7fd40dd2d4c7897512f5cd7e6bfc48935
Change-Id: I763c7ed7fd40dd2d4c7897512f5cd7e6bfc48935
diff --git a/main.cpp b/main.cpp
index 30ad85f..62d97c3 100644
--- a/main.cpp
+++ b/main.cpp
@@ -16,9 +16,9 @@
 
 #include "AST.h"
 #include "Coordinator.h"
-#include "Hash.h"
 #include "Scope.h"
 
+#include <hidl-hash/Hash.h>
 #include <hidl-util/Formatter.h>
 #include <hidl-util/FQName.h>
 #include <hidl-util/StringHelper.h>