SYCL "simulation only" runtime statistics misleading

[jtramm]

For the SYCL version, we are currently reporting runtime statistics for both the kernel initialization / JIT compiling as well as the actual execution. This may result in some issues on certain systems, e.g.:

Total Time Statistics (SYCL+OpenCL Init / JIT Compilation + Simulation Kernel)
Runtime:                XXXXXXX seconds
Lookups:               XXXXXXXXXX
Lookups/s:            XXXXXXXXXX
Simulation Kernel Only Statistics
Runtime:               0.00001 seconds
Lookups/s:             1,000,000,000,000,000
Verification checksum: (Valid)

Timing these things as we are now included some assumptions as to the asynchronous behavior of SYCL that do not appear to be true in all cases with all compilers on all machines. Instead, we should just time only the total runtime.