serial: amba-pl011: Fix serial port discard interrupt when interrupt signal...

serial: amba-pl011: Fix serial port discard interrupt when interrupt signal line of serial port is connected to mbigen.

ascend inclusion
category: bugfix
Bugzilla: https://gitee.com/openeuler/kernel/issues/I4K2U5


CVE: N/A

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Hisi when designing ascend chip, connect the serial port interrupt
signal lines to mbigen equipment, mbigen write GICD_SETSPI_NSR
register trigger the SPI interrupt. This can result in serial
port drop interrupts.

Signed-off-by: Xu Qiang <xuqiang36@huawei.com>
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>