[PATCH] x86: roll all the cpuid asm into one __cpuid call

It's a little neater, and also means only one place to patch for
paravirtualization.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>