drivers/irqchip: add sw64 interrupt controller support

Sunway inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5GDHC



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Add a driver for the SW64 implementation of the CPU interrupt
controller(INTC). In fact, the INTC is just a software simulated
module to connect global interrupt sources to the local interrupt
controller on each core.

In addition, we rename irq-lpc.c and SW64_CHIP3_LPC config.

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

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