ARM: S5P6442: Add IRQ support

This patch adds IRQ support for S5P6442. This patch adds interrupt
register definitions, IRQ definitions for various interrupt sources
and new VIC base for VIC2 in plat-s5p common irq code.

Signed-off-by: Adityapratap Sharma <aditya.ps@samsung.com>
Signed-off-by: Atul Dahiya <atul.dahiya@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>