Replace rdcycle instruction with rdtime
Replace rdcycle instruction with rdtime

The original rdcycle intent was for timestamp. In RISC-V the proper
equivalent of x86 "rdtsc" is "rdtime".

* http://lists.infradead.org/pipermail/linux-riscv/2022-September/018862.html

This reverts commit b6007bd.

google/highway,google/highway,google/highway