forked from Mirrors/opensbi

A RISC-V platform can leave unimplemented MHPM counters hard-wired to zero. We extend hart_detect_features() to detect MHPM counters which are accessible and not hard-wired to zero. We also print number of available MHPM counters as part of boot prints. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>