opc_compute_ip_reservation does not expose the assigned IP address

[scross01]

Assigned IP address attribute should be available so it can be used when creating security lists, e.g.

resource "opc_compute_ip_reservation" "ip-reservation-1" {
	parentpool = "/oracle/public/ippool"
	permanent = true
}

resource "opc_compute_security_ip_list" "sec-list-1" {
	name = "sec-list-1"
	ip_entries = ["${opc_compute_ip_reservation.ip-reservation-1.ip}"]
}