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

Bug: N/A
Test: builds
Change-Id: I98fc6a1a3c0be1c90b1deb35b54f36ab16a202ac
diff --git a/cc/config/arm_device.go b/cc/config/arm_device.go
index f093563..7110ccb 100644
--- a/cc/config/arm_device.go
+++ b/cc/config/arm_device.go
@@ -216,7 +216,7 @@
 	pctx.StaticVariable("ArmCflags", strings.Join(armCflags, " "))
 	pctx.StaticVariable("ArmLdflags", strings.Join(armLdflags, " "))
 	pctx.StaticVariable("ArmCppflags", strings.Join(armCppflags, " "))
-	pctx.StaticVariable("ArmIncludeFlags", bionicHeaders("arm", "arm"))
+	pctx.StaticVariable("ArmIncludeFlags", bionicHeaders("arm"))
 
 	// Extended cflags