cpu-all.h: fix cpu_get_real_ticks() #ifdef

Reported-by: NHervé Poussineau <hpoussin@reactos.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

cpu-all.h

@@ -1017,7 +1017,8 @@ static inline int64_t cpu_get_real_ticks (void)
 #endif
 }
 
-#elif (defined(__mips_isa_rev) && __mips_isa_rev >= 2) || defined(__linux__)
+#elif defined(__mips__) && \
+      ((defined(__mips_isa_rev) && __mips_isa_rev >= 2) || defined(__linux__))
 /*
  * binutils wants to use rdhwr only on mips32r2
  * but as linux kernel emulate it, it's fine