tools x86 headers: Update required-features.h header from the kernel

To pick the changes from:

  ecac7181

 ("x86/paravirt: Use CONFIG_PARAVIRT_XXL instead of CONFIG_PARAVIRT")

That don entail any changes in tooling, just addressing these perf tools
build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/required-features.h' differs from latest version at 'arch/x86/include/asm/required-features.h'
  diff -u tools/arch/x86/include/asm/required-features.h arch/x86/include/asm/required-features.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>