amd64/fpu: Track supervisor state XSAVE components

[bnovkov]

Summary

The amd64/fpu.c xsave_* routines track supported XSAVE components and
features. However, they only track supported user state components, and
there is currently no way for a consumer to check whether the CPU
supports a supervisor state component. Fix this by saving the supported
supervisor state components, enumerated by CPUID function 0DH,
sub-function 1, in a separate mask.

[kib]

sys/amd64/amd64/fpu.c

427

At least for me it is cleaner

[bnovkov]

sys/amd64/amd64/fpu.c

427

I agree, I'll change this in the commit.