x86: provide __parainstructions section

This patch adds the __parainstructions section to vmlinux.lds.S.
It's needed for the patching system.

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>