Add Changelog

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/ChangeLog.d/sha256-armce-arm.txt b/ChangeLog.d/sha256-armce-arm.txt
new file mode 100644
index 0000000..aaa6e39
--- /dev/null
+++ b/ChangeLog.d/sha256-armce-arm.txt
@@ -0,0 +1,4 @@
+Features
+    * Support Armv8 Crypto Extension acceleration for SHA-256
+      when compiling for Thumb or 32-bit Arm.
+