x86/cpufeature: Enable new AVX-512 features

x86/cpufeature: Enable new AVX-512 features

A few new AVX-512 instruction groups/features are added in cpufeatures.h
for enuermation: AVX512DQ, AVX512BW, and AVX512VL.

Clear the flags in fpu__xstate_clear_all_cpu_caps().

The specification for latest AVX-512 including the features can be found at:

  https://software.intel.com/sites/default/files/managed/07/b7/319433-023.pdf

Note, I didn't enable the flags in KVM. Hopefully the KVM guys can pick up
the flags and enable them in KVM.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Ravi V Shankar <ravi.v.shankar@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm@vger.kernel.org
Link: http://lkml.kernel.org/r/1457667498-37357-1-git-send-email-fenghua.yu@intel.com
[ Added more detailed feature descriptions. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>