adb: move fdevent to its own folder.

Preparatory refactoring for platform-specific implementations.

Test: mma
Change-Id: I0f600122ac89241788c5f3300f362fd9ef02ddcd
diff --git a/adb/adb.h b/adb/adb.h
index 3a6f059..352b2fe 100644
--- a/adb/adb.h
+++ b/adb/adb.h
@@ -26,7 +26,7 @@
 #include <android-base/macros.h>
 
 #include "adb_trace.h"
-#include "fdevent.h"
+#include "fdevent/fdevent.h"
 #include "socket.h"
 #include "types.h"
 #include "usb.h"