drm_hwcomposer: CI: Raise clang-tidy level from NONE to COARSE for *.h

To improve CI coverage.

Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
diff --git a/drm/ResourceManager.h b/drm/ResourceManager.h
index bb91882..b02bf36 100644
--- a/drm/ResourceManager.h
+++ b/drm/ResourceManager.h
@@ -17,7 +17,7 @@
 #ifndef RESOURCEMANAGER_H
 #define RESOURCEMANAGER_H
 
-#include <string.h>
+#include <cstring>
 
 #include "DrmDevice.h"
 #include "DrmFbImporter.h"
@@ -40,7 +40,7 @@
   int getDisplayCount() const {
     return num_displays_;
   }
-  bool ForcedScalingWithGpu() {
+  bool ForcedScalingWithGpu() const {
     return scale_with_gpu_;
   }