ARM: 9163/1: amba: Move of_amba_device_decode_irq() into amba_probe()

Similar to other resources the AMBA bus "gets" for the device,
move irq obtain from amba_device_add() to amba_probe().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>