docs: release-notes: Add note on name clash fix

Adds a note about the name clash fix for zephyr

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>
diff --git a/docs/release-notes.d/fix-zephyr-sysbuild-name.md b/docs/release-notes.d/fix-zephyr-sysbuild-name.md
new file mode 100644
index 0000000..1e241b6
--- /dev/null
+++ b/docs/release-notes.d/fix-zephyr-sysbuild-name.md
@@ -0,0 +1,2 @@
+- Fixed clash when using sysbuild with other
+  applications (i.e. tests) using the name sysbuild