lib: sbi: Rename sbi_hsm_hart_started_mask() function

A hart can take interrupt in the new HSM states introduced by the
SBI HSM suspend function (such as SUSPENDED state) so we rename
sbi_hsm_hart_started_mask() to something more generic such as
sbi_hsm_hart_interruptible_mask().

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