Remove: rdtsc and TIC/TOC based on CPU ticks (#11856)

Use TIC/TOC based on std::chrono instead. This information is also
easier to compare with others, as although it depends on CPU, it
means a bit more if "yours takes 4ms and mine takes 10ms".

src/cpu.h

@@ -10,12 +10,6 @@
 #ifndef CPU_H
 #define CPU_H
 
-/**
- * Get the tick counter from the CPU (high precision timing).
- * @return The count.
- */
-uint64_t ottd_rdtsc();
-
 /**
  * Get the CPUID information from the CPU.
  * @param info The retrieved info. All zeros on architectures without CPUID.