Added max and min width extension to rt

[JPietrzykTUD]

Added the following two types to tsl::runtime::cpu:

• max_width_extension_t (holds extension with highest degree of data-level-parallelism)
• min_width_extension_t (holds extension with minimum degree of data-level-parallelism > 1)

This can be used as shown in examples/oneAPIfpga/clz_rtl_example.cpp line 22:

using namespace tsl;
executor<runtime::cpu> cpu_executor;
using cpu_simd = simd<uint32_t, typename runtime::cpu::max_width_extension_t>;