ASoC: rt298: disable IRQ when jack is NULL

Disable IRQ when jack is NULL in rt298_mic_detect. So machine driver
can use it in suspend/resume.

Signed-off-by: Bard Liao <bardliao@realtek.com>
Reviewed-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>