forked from Mirrors/opensbi

This needs to be in the base PLIC driver as part of the power management save/restore flow. This is also in preparation for moving the PLIC information in the scratch area to the base PLIC driver. After that change, the FDT PLIC layer will be unable to look up the `struct plic_data` after cold boot. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org>