Add documentation on current behavior for X86

[toor1245]

[toor1245]

@gchatelet, @Mizux, please review PR

[toor1245]

ping

[toor1245]

@gchatelet, I updated PR, but there is a question related to GetX86CacheInfo, I see that the comment describes that it works only on Intel CPUs, but it works on AMD (new) and Hygon processors. May I update this information or did you do it on purpose?

// Returns cache hierarchy informations.
// Can call cpuid multiple times.
// Only works on Intel CPU at the moment.
CacheInfo GetX86CacheInfo(void);

[gchatelet]

@toor1245 the comment is outdated, yes please remove the part about "Intel only"

[gchatelet]

I'll squash and merge the PR once the typo is fixed. Thx a lot for the documentation!