MIPS: perf: Add hardware perf events support for new Loongson-3

New Loongson-3 means Loongson-3A R2 (Loongson-3A2000) and newer CPUs.
Loongson-3 processors have three types of PMU types (so there are three
event maps): Loongson-3A1000/Loonngson-3B1000/Loongson-3B1500 is Type-1,
Loongson-3A2000/Loongson-3A3000 is Type-2, Loongson-3A4000+ is Type-3.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/include/asm/mach-loongson64/cpu-feature-overrides.h

@@ -48,5 +48,6 @@
 #define cpu_hwrena_impl_bits	0xc0000000
 #define cpu_has_mac2008_only	1
 #define cpu_has_mips_r2_exec_hazard 0
+#define cpu_has_perf_cntr_intr_bit	0
 
 #endif /* __ASM_MACH_LOONGSON64_CPU_FEATURE_OVERRIDES_H */