Create an inline function for clflush(), with the proper arguments,
and use it instead of hard-coding the instruction.

This also removes one instance of hard-coded wbinvd, based on a patch
by Bauder de Oliveira Costa.

[ tglx: arch/x86 adaptation ]

Cc: Andi Kleen <andi@firstfloor.org>
Cc: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>