x86/paravirt: Use a single ops structure

Instead of using six globally visible paravirt ops structures combine
them in a single structure, keeping the original structures as
sub-structures.

This avoids the need to assemble struct paravirt_patch_template at
runtime on the stack each time apply_paravirt() is being called (i.e.
when loading a module).

[ tglx: Made the struct and the initializer tabular for readability sake ]

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Cc: virtualization@lists.linux-foundation.org
Cc: akataria@vmware.com
Cc: rusty@rustcorp.com.au
Cc: boris.ostrovsky@oracle.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/20180828074026.820-9-jgross@suse.com

arch/x86/xen/irq.c

@@ -128,6 +128,6 @@ static const struct pv_irq_ops xen_irq_ops __initconst = {
 
 void __init xen_init_irq_ops(void)
 {
-	pv_irq_ops = xen_irq_ops;
+	pv_ops.irq = xen_irq_ops;
 	x86_init.irqs.intr_init = xen_init_IRQ;
 }