west.yml: update hal_xtensa for intel_adsp_ace15_mtpm

This udpates the manifest SHA to use the latest Xtensa HAL
commit which is to support building intel_adsp_ace15_mtpm
using Zephyr SDK.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>