[test-suite] Add C-SKY Support in benchmark

Use gettimeofday to get the number of cycles since power-on in CSKY backend.

Differential Revision: https://reviews.llvm.org/D100926

Author: zixuan-wu

MicroBenchmarks/libs/benchmark/src/cycleclock.h

@@ -173,7 +173,7 @@ inline BENCHMARK_ALWAYS_INLINE int64_t Now() {
   struct timeval tv;
   gettimeofday(&tv, nullptr);
   return static_cast<int64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;
-#elif defined(__loongarch__)
+#elif defined(__loongarch__) || defined(__csky__)
   struct timeval tv;
   gettimeofday(&tv, nullptr);
   return static_cast<int64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;