drm_hwcomposer: Rename DrmResources to DrmDevice

DrmDevice is a better name to reflect the fact that DrmResources/
DrmDevice can handle just one dri node.

Suggested here [1] by Sean Paul.
[1] https://lists.freedesktop.org/archives/dri-devel/2018-April/173290.html

Signed-off-by: Alexandru Gheorghe <alexandru-cosmin.gheorghe@arm.com>
diff --git a/vsyncworker.h b/vsyncworker.h
index 787152e..3d3a805 100644
--- a/vsyncworker.h
+++ b/vsyncworker.h
@@ -17,7 +17,7 @@
 #ifndef ANDROID_EVENT_WORKER_H_
 #define ANDROID_EVENT_WORKER_H_
 
-#include "drmresources.h"
+#include "drmdevice.h"
 #include "worker.h"
 
 #include <map>
@@ -40,7 +40,7 @@
   VSyncWorker();
   ~VSyncWorker() override;
 
-  int Init(DrmResources *drm, int display);
+  int Init(DrmDevice *drm, int display);
   void RegisterCallback(std::shared_ptr<VsyncCallback> callback);
 
   void VSyncControl(bool enabled);
@@ -52,7 +52,7 @@
   int64_t GetPhasedVSync(int64_t frame_ns, int64_t current);
   int SyntheticWaitVBlank(int64_t *timestamp);
 
-  DrmResources *drm_;
+  DrmDevice *drm_;
 
   // shared_ptr since we need to use this outside of the thread lock (to
   // actually call the hook) and we don't want the memory freed until we're