Fix dependency on IOMX in OMXClient.h

Change-Id: I5bc970c770f6e603b2e1cf27a705fdf7fe266329
diff --git a/media/libstagefright/include/media/stagefright/OMXClient.h b/media/libstagefright/include/media/stagefright/OMXClient.h
index 2f159b0..b1864b8 100644
--- a/media/libstagefright/include/media/stagefright/OMXClient.h
+++ b/media/libstagefright/include/media/stagefright/OMXClient.h
@@ -18,9 +18,9 @@
 
 #define OMX_CLIENT_H_
 
-namespace android {
+#include <media/IOMX.h>
 
-class IOMX;
+namespace android {
 
 class OMXClient {
 public: