x86/cpufeatures: Enable new AVX512 cpu features

Add a few new AVX512 instruction groups/features for enumeration in
/proc/cpuinfo: AVX512IFMA and AVX512VBMI.

Clear the flags in fpu_xstate_clear_all_cpu_caps().

CPUID.(EAX=7,ECX=0):EBX[bit 21] AVX512IFMA
CPUID.(EAX=7,ECX=0):ECX[bit 1]  AVX512VBMI

Detailed information of cpuid bits for the features can be found at
https://bugzilla.kernel.org/show_bug.cgi?id=187891

Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: mingo@elte.hu
Link: http://lkml.kernel.org/r/1479327060-18668-1-git-send-email-gayatri.kammela@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>