drm_hwcomposer: Change return type of DrmProperty::value() to tuple

To keep consistent with other functions

Change-Id: I11ba07eabcee08f3db09b3a5422bc480482a62c1
Signed-off-by: Sean Paul <seanpaul@chromium.org>
diff --git a/drmproperty.h b/drmproperty.h
index f1328fe..36cd63d 100644
--- a/drmproperty.h
+++ b/drmproperty.h
@@ -45,7 +45,7 @@
   uint32_t id() const;
   std::string name() const;
 
-  int value(uint64_t *value) const;
+  std::tuple<int, uint64_t> value() const;
   bool immutable() const;
 
  private: