adb: move fdevent to its own folder.

Preparatory refactoring for platform-specific implementations.

Test: mma
Change-Id: I0f600122ac89241788c5f3300f362fd9ef02ddcd
diff --git a/socket.h b/socket.h
index b8c559a..4276851 100644
--- a/socket.h
+++ b/socket.h
@@ -24,7 +24,7 @@
 #include <string>
 
 #include "adb_unique_fd.h"
-#include "fdevent.h"
+#include "fdevent/fdevent.h"
 #include "types.h"
 
 class atransport;