manifest: Update Zephyr with cpu_load module

Add cpu_load module from upstream.

Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>

Author: nordic-krch

west.yml

@@ -65,7 +65,7 @@ manifest:
     # https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/guides/modules.html
     - name: zephyr
       repo-path: sdk-zephyr
-      revision: c9113a87822e123bd287568c957d92b35502e5d1
+      revision: pull/2657/head
       import:
         # In addition to the zephyr repository itself, NCS also
         # imports the contents of zephyr/west.yml at the above