Unified sysroot: arch-X/include directories are gone.

Bug: N/A
Test: builds
Change-Id: I98fc6a1a3c0be1c90b1deb35b54f36ab16a202ac
diff --git a/cc/config/arm64_device.go b/cc/config/arm64_device.go
index 0d22ed4..390936a 100644
--- a/cc/config/arm64_device.go
+++ b/cc/config/arm64_device.go
@@ -117,7 +117,7 @@
 	pctx.StaticVariable("Arm64Cflags", strings.Join(arm64Cflags, " "))
 	pctx.StaticVariable("Arm64Ldflags", strings.Join(arm64Ldflags, " "))
 	pctx.StaticVariable("Arm64Cppflags", strings.Join(arm64Cppflags, " "))
-	pctx.StaticVariable("Arm64IncludeFlags", bionicHeaders("arm64", "arm64"))
+	pctx.StaticVariable("Arm64IncludeFlags", bionicHeaders("arm64"))
 
 	pctx.StaticVariable("Arm64ClangCflags", strings.Join(ClangFilterUnknownCflags(arm64Cflags), " "))
 	pctx.StaticVariable("Arm64ClangLdflags", strings.Join(ClangFilterUnknownCflags(arm64Ldflags), " "))