Reorganize system/keymaster.

This CL moves the includes that should be exported to include/ and
removes the trusty-specific code (some of which is moving to
hardware/google and some of which is moving to the trusty tree.)

Change-Id: Ie4fabf6b5c5f36b50c2f5ff356548ca2e9140fcb
diff --git a/google_keymaster.cpp b/google_keymaster.cpp
index 18b1318..448dd05 100644
--- a/google_keymaster.cpp
+++ b/google_keymaster.cpp
@@ -24,9 +24,10 @@
 
 #include <UniquePtr.h>
 
+#include <keymaster/google_keymaster.h>
+#include <keymaster/google_keymaster_utils.h>
+
 #include "ae.h"
-#include "google_keymaster.h"
-#include "google_keymaster_utils.h"
 #include "key.h"
 #include "key_blob.h"
 #include "operation.h"