Combine changelog entries for muladdc assembly fix

Combine the changelog entries for the memory constraints fix on
aarch64 and amd64, since these are essentially fixing the same
issue.

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/ChangeLog.d/muladdc-aarch64-memory.txt b/ChangeLog.d/muladdc-aarch64-memory.txt
deleted file mode 100644
index 70addd2..0000000
--- a/ChangeLog.d/muladdc-aarch64-memory.txt
+++ /dev/null
@@ -1,4 +0,0 @@
-Bugfix
-    * Add missing memory constraints in aarch64 inline assembly for
-      bignum multiplication.
-      Fixes #4962.
diff --git a/ChangeLog.d/muladdc-amd64-memory.txt b/ChangeLog.d/muladdc-amd64-memory.txt
deleted file mode 100644
index b834331..0000000
--- a/ChangeLog.d/muladdc-amd64-memory.txt
+++ /dev/null
@@ -1,4 +0,0 @@
-Bugfix
-   * Fix missing constraints on x86_64 assembly code for bignum multiplication
-     that broke some bignum operations with (at least) Clang 12.
-     Fixes #4116, #4786, #4917.
diff --git a/ChangeLog.d/muladdc-memory.txt b/ChangeLog.d/muladdc-memory.txt
new file mode 100644
index 0000000..218be5a
--- /dev/null
+++ b/ChangeLog.d/muladdc-memory.txt
@@ -0,0 +1,5 @@
+Bugfix
+   * Fix missing constraints on x86_64 and aarch64 assembly code
+     for bignum multiplication that broke some bignum operations with
+     (at least) Clang 12.
+     Fixes #4116, #4786, #4917, #4962.