irqchip/sun4i: Add support for Allwinner ARMv5 F1C100s

This patch adds support for suniv Allwinner ARMv5 F1C100s SoC which has
stripped version of interrupt controller that found in A10/A13.

Signed-off-by: Mesih Kilinc <mesihkilinc@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>