Replace the x86 XGETBV instruction with its opcode bytes

Replace the x86 XGETBV instruction with its opcode bytes

This is a new instruction, present on the SandyBridge architecture and
later. Some older assemblers do not support it and produce:

  {standard input}:225:no such instruction: `xgetbv'

The use of this instruction is protected by a CPUID check (function 1,
ECX bit 27), so we only run it in processors that do support it.

Change-Id: Ife7500c0deaab9539074835a4511e8c19602608e
Reviewed-by: Bradley T. Hughes <bradley.hughes@nokia.com>