Please only depend on libcpuinfo for aarch64 and x86_64

Hello,

Following a report for Fedora's svt-av1 package, we are trying to properly unbundle third party libraries used by svt-av1 (also reported by Yoong Jin in #2214 ).

Regarding libcpuinfo, it is only built in Fedora on aarch64 and x86_64, as it is stated on upstream README.md:

x86, x86-64, ARM, and ARM64 architectures

(we dropped x86_32 and ARM32 a couple of years ago).

If we built with the bundled version, there is no issue, but with system wide, it prevents us from keeping svt-av1 on ppc64le and s390x (and soon riscv64).

Although there is limited use for svt-av1 on other arch for which you do not provide ASM, we still want to provide packages for these architectures.

Thus, would it be possible to conditionally only depend on libcpuinfo for their officially supported arch (x86, x86-64, ARM, and ARM64), and built without it for the other arches ?

Thank you.