* @link: link number which represents a PIRQ
* @irq: the 8259 IRQ number
* @return: true if the irq is already routed to 8259 for a given link,
* false elsewise
*/
* @link: link number which represents a PIRQ
* @irq: the 8259 IRQ number
* @return: true if the irq is already routed to 8259 for a given link,
* false elsewise
*/