target/arm: Split out aa32_max_features

Share the code to set AArch32 max features so that we no
longer have code drift between qemu{-system,}-{arm,aarch64}.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-9-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/target/arm/internals.h b/target/arm/internals.h
index 343b465..c563b37 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -1313,4 +1313,6 @@
 void define_cortex_a72_a57_a53_cp_reginfo(ARMCPU *cpu);
 #endif
 
+void aa32_max_features(ARMCPU *cpu);
+
 #endif