Detect AMD Zen 5 microarchitecture

[fbarchard]

Detect AMD Family 26 with any model as cpuinfo_uarch_zen5

[digantdesai]

From @fbarchard

The reason for wanting zen5 is avx512 on AMD and Intel behave differently
AMD prefers short/wide tile sizes such as 6x64
Intel prefers tall/narrow tile sizes such as 13x32
Also GFNI is present on both, but GFNI is slow on AMD Zen4
And int32 multiply is very slow on Intel but fast on AMD.

[digantdesai]

riscv failure seems unrelated.