xen: rename dom0_op to platform_op

The dom0_op hypercall has been renamed to platform_op since Xen 3.2,
which is ancient, and modern upstream Linux kernels cannot run as dom0
and it anymore anyway.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
diff --git a/drivers/xen/xen-acpi-pad.c b/drivers/xen/xen-acpi-pad.c
index f83b754..23d1808 100644
--- a/drivers/xen/xen-acpi-pad.c
+++ b/drivers/xen/xen-acpi-pad.c
@@ -36,7 +36,7 @@
 	op.u.core_parking.type = XEN_CORE_PARKING_SET;
 	op.u.core_parking.idle_nums = idle_nums;
 
-	return HYPERVISOR_dom0_op(&op);
+	return HYPERVISOR_platform_op(&op);
 }
 
 static int xen_acpi_pad_idle_cpus_num(void)
@@ -46,7 +46,7 @@
 	op.cmd = XENPF_core_parking;
 	op.u.core_parking.type = XEN_CORE_PARKING_GET;
 
-	return HYPERVISOR_dom0_op(&op)
+	return HYPERVISOR_platform_op(&op)
 	       ?: op.u.core_parking.idle_nums;
 }