genirq: Introduce helper function irq_data_get_node()

genirq: Introduce helper function irq_data_get_node()

Introduce helper function irq_data_get_node() and variants thereof to
hide struct irq_data implementation details.

Convert the core code to use them.

Signed-off-by: Jiang Liu <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Yinghai Lu <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Jason Cooper <[email protected]>
Cc: Kevin Cernekee <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>