ARM: 7183/1: vic: register the VIC for ST-modified VIC's

When probing the VIC, the ST variant has a different probing method to
account for the extra interrupts which meant we didn't previously call
vic_register() which registered the irq_domain.

Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>