drm_hwcomposer: update #include's for drm_hwcomposer.h

That's the second most important part of renaming a file.

Change-Id: If9280f3b360389ef17b798e162a9c3b0c0a3133b
diff --git a/importer.h b/importer.h
index 8bd40da..1fc822c 100644
--- a/importer.h
+++ b/importer.h
@@ -17,7 +17,7 @@
 #ifndef ANDROID_DRM_IMPORTER_H_
 #define ANDROID_DRM_IMPORTER_H_
 
-#include "drm_hwcomposer.h"
+#include "drmhwcomposer.h"
 
 #include <hardware/hardware.h>
 #include <hardware/hwcomposer.h>