irqchip: Add Kconfig symbols for sunxi drivers

Not all of these drivers are needed on every ARCH_SUNXI platform. In
particular, the ARCH_SUNXI symbol will be reused for the Allwinner D1,
a RISC-V SoC which contains none of these irqchips.

Introduce Kconfig symbols so we can select only the drivers actually
used by a particular set of platforms. This also lets us move the
irqchip driver dependencies to a more appropriate location.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220509034941.30704-1-samuel@sholland.org