ace: power: fix d0i3 restore

The restore vector after power gating was configuring the MEMCTL register
incorrectly. This caused an FW crash during the cache prefetch.

Additionally, since lp sram cache issue was fixed, xtensa hal function
can be replace with zephyr equivalent.

Signed-off-by: Tomasz Leman <tomasz.m.leman@intel.com>