irqchip/ls-extirq: Add LS1043A, LS1088A external interrupt support

Add an new IRQ chip declaration for LS1043A and LS1088A, and cleanup
the use of the "bit_reverse" property, now gated on the Soc type.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Biwen Li <biwen.li@nxp.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201130101515.27431-1-biwen.li@oss.nxp.com