Don't warn about DT_FLAGS_1 containing DF_1_PIE

DF_1_PIE is set in PIE code built with gcc 6.x. The flag is purely
informational and the linker doesn't need to do anything about it,
so Bionic handles it correctly - no need to warn.

Change-Id: If99c1742fe22f8842a84818909ed961716ef5ca5
Signed-off-by: Bernhard Rosenkränzer <Bernhard.Rosenkranzer@linaro.org>
diff --git a/linker/linker.h b/linker/linker.h
index aa6d00b..4787471 100644
--- a/linker/linker.h
+++ b/linker/linker.h
@@ -67,7 +67,7 @@
 #define ELF64_R_TYPE(info)  (((info) >> 56) & 0xff)
 #endif
 
-#define SUPPORTED_DT_FLAGS_1 (DF_1_NOW | DF_1_GLOBAL | DF_1_NODELETE)
+#define SUPPORTED_DT_FLAGS_1 (DF_1_NOW | DF_1_GLOBAL | DF_1_NODELETE | DF_1_PIE)
 
 // Class used construct version dependency graph.
 class VersionTracker {