refactor(cpus): rename errata_report.h to errata.h

The ERRATA_XXX macros, used in cpu_helpers.S, are necessary for the
check_errata_xxx family of functions. The CPU_REV should be used in the
cpu files but for whatever reason the values have been hard-coded so far
(at the cost of readability). It's evident this file is not strictly for
status reporting.

The new purpose of this file is to make it a one-stop-shop for all
things errata.

Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: I1ce22dd36df5aa0bcfc5f2772251f91af8703dfb
diff --git a/lib/cpus/aarch64/dsu_helpers.S b/lib/cpus/aarch64/dsu_helpers.S
index 419b6ea..b7e028a 100644
--- a/lib/cpus/aarch64/dsu_helpers.S
+++ b/lib/cpus/aarch64/dsu_helpers.S
@@ -6,7 +6,7 @@
 
 #include <asm_macros.S>
 #include <dsu_def.h>
-#include <lib/cpus/errata_report.h>
+#include <lib/cpus/errata.h>
 
 	/* -----------------------------------------------------------------------
 	 * DSU erratum 798953 check function