MIPS: only register MT SMP ops if MT is supported

Verify that the current CPU actually supports multi-threading before
registering MT SMP ops, instead of unconditionally registering them if
the kernel is compiled with CONFIG_MIPS_MT_SMP.
Suggested-by: NJiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: NSander Vanheule <sander@svanheule.net>
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/include/asm/smp-ops.h

@@ -101,6 +101,9 @@ static inline int register_vsmp_smp_ops(void)
 #ifdef CONFIG_MIPS_MT_SMP
 	extern const struct plat_smp_ops vsmp_smp_ops;
 
+	if (!cpu_has_mipsmt)
+		return -ENODEV;
+
 	register_smp_ops(&vsmp_smp_ops);
 
 	return 0;