lib: sbi: Auto start domain only if boot HART within limits

The sbi_domain_finalize() should auto start a domain only if the
boot HART is withing limits (i.e. less than SBI_HARTMASK_MAX_BITS).

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>