[WIP] arch: riscv: smp: add PLIC-based IPI#81260

ycsin wants to merge 2 commits intozephyrproject-rtos:mainzephyrproject-rtos/zephyr:mainfrom

ycsin:pr/riscv-ipi-plic-altycsin/zephyr:pr/riscv-ipi-plic-altCopy head branch name to clipboard