intel_adsp/ace: power: Lock interruption when power gate fails

In case the core is not power gated, waiti will restore intlevel. In
this case we lock interruption after it.

In the bug scenario, the host starts streaming and via SOF APIs, keeps a
lock to prevent Zephyr from entering PM_STATE_RUNTIME_IDLE. During the
test case, host removes this block and core0 is allowed to enter IDLE
state.

When core0 enters power gated state, interrrupts are left enabled (so
the core can be woken up when something happens). This leaves a race
where suitably timed interrupt will actually block entry to power gated
state and k_cpu_idle() in power_gate_entry() will return. This is rare,
but happens often enough that the relatively short test plan run on SOF
pull-requests will trigger this case.

Fixes #69807

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
(cherry picked from commit 07426a80)