fix(errata): workaround for Cortex-A510 erratum 2347730

Cortex-A510 erratum 2347730 is a Cat B erratum that affects
revisions r0p0, r0p1, r0p2, r0p3, r1p0 and r1p1. It is
fixed in r1p2. The workaround is to set CPUACTLR_EL1[17]
to 1, which will disable specific microarchitectural clock
gating behaviour.

SDEN can be found here:
https://developer.arm.com/documentation/SDEN1873351/latest
https://developer.arm.com/documentation/SDEN1873361/latest

Signed-off-by: Akram Ahmad <Akram.Ahmad@arm.com>
Change-Id: I115386284c2d91bd61515142f971e2e72de43e68
diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 8a86b61..52e1c7d 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -597,6 +597,10 @@
    Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
    r0p3 and r1p0, it is fixed in r1p1.
 
+- ``ERRATA_A510_2347730``: This applies errata 2347730 workaround to
+   Cortex-A510 CPU. This needs to be enabled for revisions r0p0, r0p1, r0p2,
+   r0p3, r1p0 and r1p1. It is fixed in r1p2.
+
 -  ``ERRATA_A510_2371937``: This applies errata 2371937 workaround to
    Cortex-A510 CPU. This needs to applied for revisions r0p0, r0p1, r0p2,
    r0p3, r1p0, r1p1, and is fixed in r1p2.