Read both registers as the first step in the interrupt handler to make
sure that we are handling the event which triggered the interrupt.

The delayed reading of the target request register might reflect incorrect
information about the reason why the interrupt was risen.

Note also that the IPC3 interrupt handler is implemented in this way also.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Link: https://lore.kernel.org/r/20221018124008.6846-3-peter.ujfalusi@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>