target/arm: Add support for FEAT_NMI, Non-maskable Interrupt

Add support for FEAT_NMI. NMI (FEAT_NMI) is an mandatory feature in
ARMv8.8-A and ARM v9.3-A.

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: 20240407081733.3231820-4-ruanjinjie@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/internals.h

@@ -1229,6 +1229,9 @@ static inline uint32_t aarch64_pstate_valid_mask(const ARMISARegisters *id)
     if (isar_feature_aa64_mte(id)) {
         valid |= PSTATE_TCO;
     }
+    if (isar_feature_aa64_nmi(id)) {
+        valid |= PSTATE_ALLINT;
+    }
 
     return valid;
 }