backports: empty define for __ro_after_init

nl80211 now uses section qualifier __ro_after_init. However, this
is not available in kernels before v4.6. Neither is the section
itself hence adding an empty define in backports.

Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/backport/backport-include/linux/cache.h b/backport/backport-include/linux/cache.h
new file mode 100644 (file)
index 0000000..bd7cdcf
--- /dev/null
+++ b/backport/backport-include/linux/cache.h
@@ -0,0 +1,10 @@
+#ifndef _BACKPORT_CACHE_H
+#define _BACKPORT_CACHE_H
+
+#include_next <linux/cache.h>
+
+#ifndef __ro_after_init
+#define __ro_after_init
+#endif
+
+#endif /* _BACKPORT_CACHE_H */