hwtracing: hisi_ptt: Disable interrupt after trace end

On trace end we disable the hardware but leave the interrupt
unmasked. Mask the interrupt to make the process reverse to
the start. No actual issue since hardware should send no
interrupt after disabled.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20231010084731.30450-2-yangyicong@huawei.com