target/ppc: fix signal delivery for ppc64abi32

We were incorrectly using the 64-bit AIX ABI instead of the 32-bit
SYSV ABI for setting NIP for the signal handler.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Reviewed-by: NLaurent Vivier <laurent@vivier.eu>

linux-user/ppc/signal.c

@@ -501,7 +501,9 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
     int i, err = 0;
 #if defined(TARGET_PPC64)
     struct target_sigcontext *sc = 0;
+#if !defined(TARGET_ABI32)
     struct image_info *image = ((TaskState *)thread_cpu->opaque)->info;
+#endif
 #endif
 
     rt_sf_addr = get_sigframe(ka, env, sizeof(*rt_sf));
@@ -557,7 +559,7 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
     env->gpr[5] = (target_ulong) h2g(&rt_sf->uc);
     env->gpr[6] = (target_ulong) h2g(rt_sf);
 
-#if defined(TARGET_PPC64)
+#if defined(TARGET_PPC64) && !defined(TARGET_ABI32)
     if (get_ppc64_abi(image) < 2) {
         /* ELFv1 PPC64 function pointers are pointers to OPD entries. */
         struct target_func_ptr *handler =