[TEST] update Zephyr to fix PTL

Update Zephyr to a PR, containing a work-around for a PTL MMU problem.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

west.yml

@@ -43,7 +43,7 @@ manifest:
 
     - name: zephyr
       repo-path: zephyr
-      revision: 658f9357b87ab3e02351a57183743ec70f92cdd7
+      revision: pull/86919/head
       remote: zephyrproject
 
       # Import some projects listed in zephyr/west.yml@revision