Refactored SEA IR folder structure to be more logical.

Change-Id: I302c79af92c07cceb38dff36efe416bfa4869a91
diff --git a/compiler/sea_ir/frontend.cc b/compiler/sea_ir/frontend.cc
index b6f84ee..87ef901 100644
--- a/compiler/sea_ir/frontend.cc
+++ b/compiler/sea_ir/frontend.cc
@@ -25,7 +25,7 @@
 #include "runtime.h"
 #include "safe_map.h"
 
-#include "sea_ir/sea.h"
+#include "sea_ir/ir/sea.h"
 #include "sea_ir/debug/dot_gen.h"
 #include "sea_ir/types/types.h"
 namespace art {