drm_hwcomposer: add non hwfb import filter

This patch adds non hwfb filter to generic drm importer
with additional property "hwc.drm.exclude_non_hwfb_imports".
By default this is set to false, and no logic changes are
happening. On setting this option to 1 the filter is being
activated on Init() function.

Change-Id: I7a718a66cb6214c051335a4589d60b5833e5c545
Signed-off-by: Mykhailo Sopiha <mykhailo.sopiha@linaro.org>
diff --git a/platform/platformdrmgeneric.h b/platform/platformdrmgeneric.h
index c6d2be6..88bff5f 100644
--- a/platform/platformdrmgeneric.h
+++ b/platform/platformdrmgeneric.h
@@ -43,6 +43,7 @@
 
  private:
   const gralloc_module_t *gralloc_;
+  bool exclude_non_hwfb_;
 };
 }  // namespace android