Cortex-A15: Implement workaround for errata 816470

Change-Id: I9755252725be25bfd0147839d7df56888424ff84
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>
diff --git a/docs/cpu-specific-build-macros.rst b/docs/cpu-specific-build-macros.rst
index 95538d0..a9ed9c1 100644
--- a/docs/cpu-specific-build-macros.rst
+++ b/docs/cpu-specific-build-macros.rst
@@ -71,6 +71,11 @@
 The value of the build flags is 0 by default, that is, disabled. A value of 1
 will enable it.
 
+For Cortex-A15, the following errata build flags are defined :
+
+-  ``ERRATA_A15_816470``: This applies errata 816470 workaround to Cortex-A15
+   CPU. This needs to be enabled only for revision >= r3p0 of the CPU.
+
 For Cortex-A53, the following errata build flags are defined :
 
 -  ``ERRATA_A53_819472``: This applies errata 819472 workaround to all