MIPS: Add cpu_vpe_id macro

The vpe_id field of struct cpuinfo_mips is only present when one of
CONFIG_MIPS_MT_{SMP,SMTC} is enabled. That means that any code accessing
which may compile without MT is currently forced to use an #ifdef.
Instead this patch provides an accessor macro, #ifdef'd appropriately
to prevent further #ifdef's elsewhere.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6646/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/cpu-info.h

@@ -95,4 +95,10 @@ extern void cpu_report(void);
 extern const char *__cpu_name[];
 #define cpu_name_string()	__cpu_name[smp_processor_id()]
 
+#if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_MIPS_MT_SMTC)
+# define cpu_vpe_id(cpuinfo)	((cpuinfo)->vpe_id)
+#else
+# define cpu_vpe_id(cpuinfo)	0
+#endif
+
 #endif /* __ASM_CPU_INFO_H */