x86/irq: Use accessor irq_data_get_node()

Use accessor irq_data_get_node() to hide struct irq_data
implementation detail, so we can move node to irq_data_common later.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>