x86: add asm_offset PARAVIRT constants

This patch adds the constant PARAVIRT needs in asm_offsets_64.c

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>