forked from Mirrors/opensbi

This patch adds a callback to fetch the number of bits implemented for a custom firmware counter. If the callback fails or is not implemented then width defaults to 63. Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Anup Patel <anup@brainfault.org>