target/arm: Add support for NMI in arm_phys_excp_target_el()

target/arm: Add support for NMI in arm_phys_excp_target_el()

According to Arm GIC section 4.6.3 Interrupt superpriority, the interrupt
with superpriority is always IRQ, never FIQ, so handle NMI same as IRQ in
arm_phys_excp_target_el().

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20240407081733.3231820-8-ruanjinjie@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>