riscv64: adapt PLO to multicore #1302

Job	Run time
call-ci / build (armv7a7-imx6ull-evk)	1m 15s
call-ci / build (armv7a9-zynq7000-qemu)	1m 14s
call-ci / build (armv7a9-zynq7000-zedboard)	1m 3s
call-ci / build (armv7a9-zynq7000-zturn)	1m 5s
call-ci / build (armv7m4-stm32l4x6-nucleo)	1m 15s
call-ci / build (armv7m7-imxrt105x-evk)	1m 12s
call-ci / build (armv7m7-imxrt106x-evk)	1m 12s
call-ci / build (armv7m7-imxrt117x-evk)	1m 12s
call-ci / build (host-generic-pc)	57s
call-ci / build (ia32-generic-pc)	1m 6s
call-ci / build (ia32-generic-qemu)	1m 5s
call-ci / build (riscv64-generic-qemu)	1m 8s
call-ci / build (riscv64-generic-spike)	57s
call-ci / build (sparcv8leon3-gr716-mini)	1m 1s
call-ci / test HW	0s
call-ci / test EMU	0s
call-ci / tests-summary	9s
call-ci / send-notification	0s
	15m 51s

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