ARM: shmobile: r8a7779: move r8a7779_init_irq_xxx() to setup

This patch moves r8a7779_init_irq_xxx() to setup code,
and remove intc-r8a7779.

Now, r8a7779_init_irq_extpin() uses
platform_device_register_resndata() instead of
platform_device_register()

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>