Added errno declaration to hardware_properties.h

Bug: 22407109
Change-Id: I1675916c811fdbec88846042f018df57a4af8963
diff --git a/modules/hardware_properties/hardware_properties.c b/modules/hardware_properties/hardware_properties.c
index d8bf037..81675e0 100644
--- a/modules/hardware_properties/hardware_properties.c
+++ b/modules/hardware_properties/hardware_properties.c
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#include <errno.h>
+
 #include <hardware/hardware.h>
 #include <hardware/hardware_properties.h>