errata: workaround for Cortex-A710 errata 1987031

Cortex-A710 erratum 1987031 is a Cat B erratum present in r0p0, r1p0,
and r2p0 of the Cortex-A710 processor core, and it is still open.

A710 SDEN: https://documentation-service.arm.com/static/61099dc59ebe3a7dbd3a8a88?token=

Signed-off-by: nayanpatel-arm <nayankumar.patel@arm.com>
Change-Id: I9bcff306f82328ad5a0f6e9836020d23c07f7179
diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 0a0d2f0..194b6c6 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -359,6 +359,12 @@
    CPU. This needs to be enabled for revisions r0p0, r1p0, and r1p1 of the
    CPU.  It is still open.
 
+For Cortex-A710, the following errata build flags are defined :
+
+-  ``ERRATA_A710_1987031``: This applies errata 1987031 workaround to
+   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
+   r2p0 of the CPU. It is still open.
+
 DSU Errata Workarounds
 ----------------------