soc/xtensa/intel_adsp/tools: Ack local interrupt before processing IPC

It seems a race can happen between the host acknowledging a DONE
interrupt and the DSP being able to mark some IPC as done. To avoid
this, the host script now always acknowledges the DONE interrupt
_before_ processing the IPC message.

Signed-off-by: Ederson de Souza <ederson.desouza@intel.com>