forked from Mirrors/opensbi

A platform hook to initialize PMU allows platform vendors to provide their own mechanism to define pmu event-counter mappings in addition to the DT based approach. Another platform hook that allows platform vendors customize the final mhpmevent value configuration. Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>