x86/fpu: Add C structures for AVX-512 state components

AVX-512 has 3 separate state components:

  1. opmask registers
  2. zmm upper half of registers 0-15
  3. new zmm registers (16-31)

This patch adds C structures for the three components along with
a few comments mostly lifted from the SDM to explain what they
do.  This will allow us to check our structures against what the
hardware tells us about the sizes of the components.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: dave@sr71.net
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20150902233129.F2433B98@viggo.jf.intel.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>