target/arm: Suppress FEAT_TRBE (Trace Buffer Extension)

Like FEAT_TRF (Self-hosted Trace Extension), suppress tracing
external to the cpu, which is out of scope for QEMU.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20230811214031.171020-10-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/cpu.c

@@ -2088,6 +2088,9 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
         /* FEAT_SPE (Statistical Profiling Extension) */
         cpu->isar.id_aa64dfr0 =
             FIELD_DP64(cpu->isar.id_aa64dfr0, ID_AA64DFR0, PMSVER, 0);
+        /* FEAT_TRBE (Trace Buffer Extension) */
+        cpu->isar.id_aa64dfr0 =
+            FIELD_DP64(cpu->isar.id_aa64dfr0, ID_AA64DFR0, TRACEBUFFER, 0);
         /* FEAT_TRF (Self-hosted Trace Extension) */
         cpu->isar.id_aa64dfr0 =
             FIELD_DP64(cpu->isar.id_aa64dfr0, ID_AA64DFR0, TRACEFILT, 0);