sw64: add builtin LPC interrupt controller to chip3.dts

Sunway inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5G7AK



--------------------------------

This adds corresponding devicetree binding for LPC interrupt
controllers on chip3 series cpu.

Signed-off-by: Zhu Donghong <zhudonghong@wxiat.com>

Signed-off-by: Gu Zitao <guzitao@wxiat.com>