drm_hwcomposer: Make Planner class fully static

clang-tidy suggested to make all methods of Planner static,
since they don't use any instance members.

This makes creation of Planner instances unnecessary, therefore
remove all such cases.

Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
diff --git a/compositor/DrmDisplayComposition.h b/compositor/DrmDisplayComposition.h
index d077aee..dcfd96e 100644
--- a/compositor/DrmDisplayComposition.h
+++ b/compositor/DrmDisplayComposition.h
@@ -30,7 +30,6 @@
 namespace android {
 
 class Importer;
-class Planner;
 
 constexpr size_t kUndefinedSourceLayer = UINT16_MAX;
 
@@ -59,7 +58,7 @@
 class DrmDisplayComposition {
  public:
   DrmDisplayComposition(const DrmDisplayComposition &) = delete;
-  DrmDisplayComposition(DrmCrtc *crtc, Planner *planner);
+  explicit DrmDisplayComposition(DrmCrtc *crtc);
   ~DrmDisplayComposition() = default;
 
   int SetLayers(DrmHwcLayer *layers, size_t num_layers);
@@ -80,13 +79,8 @@
     return crtc_;
   }
 
-  Planner *planner() const {
-    return planner_;
-  }
-
  private:
   DrmCrtc *crtc_ = nullptr;
-  Planner *planner_ = nullptr;
 
   std::vector<DrmHwcLayer> layers_;
   std::vector<DrmCompositionPlane> composition_planes_;