target/mips: Move cpu_signal_handler definition around

We have 2 blocks guarded with #ifdef for sysemu, which
are simply separated by the cpu_signal_handler definition.

To simplify the following commits which involve various
changes in internal.h, first join the sysemu-guarded blocks.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210428170410.479308-16-f4bug@amsat.org>

target/mips/internal.h

@@ -151,13 +151,12 @@ void mips_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
                                     MemTxResult response, uintptr_t retaddr);
 hwaddr cpu_mips_translate_address(CPUMIPSState *env, target_ulong address,
                                   MMUAccessType access_type, uintptr_t retaddr);
-#endif
-
-#define cpu_signal_handler cpu_mips_signal_handler
 
-#ifndef CONFIG_USER_ONLY
 extern const VMStateDescription vmstate_mips_cpu;
-#endif
+
+#endif /* !CONFIG_USER_ONLY */
+
+#define cpu_signal_handler cpu_mips_signal_handler
 
 static inline bool cpu_mips_hw_interrupts_enabled(CPUMIPSState *env)
 {