west.yml: update Zephyr to 8bec2d7b3

Includes following directly affecting SOF targets:
0891448ac9 soc: intel_adsp: don't enable interrupt before k_cpu_idl
a4b9692155 soc: intel_adsp/cavs: add secondary dsp context save support
4b02bbc329 cmake: xtensa: update xtensa SoC to use SOC_LINKER_SCRIPT
	   variable
ba7e6fa69f cmake: cleanup and simplify the standard include logic in Zephyr

Signed-off-by: Rander Wang <rander.wang@intel.com>

Author: RanderWang

west.yml

@@ -43,7 +43,7 @@ manifest:
 
     - name: zephyr
       repo-path: zephyr
-      revision: 460c2167e4f3f6489ff0d3f519466a5682d8146b
+      revision: 8bec2d7b37e14b5605f786f3ea6c0d3749fc96ab
       remote: zephyrproject
 
       # Import some projects listed in zephyr/west.yml@revision