tools: Drop xc_cpuid_check() and bindings

tools: Drop xc_cpuid_check() and bindings

There are no current users which I can locate.  One piece of xend which didn't
move forwards into xl/libxl is this:

  #   Configure host CPUID consistency checks, which must be satisfied for this
  #   VM to be allowed to run on this host's processor type:
  #cpuid_check=[ '1:ecx=xxxxxxxxxxxxxxxxxxxxxxxxxx1xxxxx' ]
  # - Host must have VMX feature flag set

The implementation of xc_cpuid_check() is conceptually broken.  Dom0's view of
CPUID is not the approprite view to check, and will be wrong in the presence
of CPUID masking/faulting, and for HVM-based toolstack domains.

If it turns out that the functionality is required, it should be implemented
in terms of XEN_SYSCTL_get_cpuid_policy to use the proper CPUID view.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>