ARM: Remove open-coded version of IRQCHIP_DECLARE

Now that the IRQCHIP_DECLARE macro has been moved to linux/irqchip.h,
it becomes possible to cleanup the open-coded versions of the same
macro that have been added to some private irqchips implementations.

Cc: Sascha Hauer <kernel@pengutronix.de>
Acked-by: Kukjin Kim <kgene@kernel.org>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Olof Johansson <olof@lixom.net>