lib: sbi: Use SBI_HSM_STATE_xyz defines instead of SBI_STATE_xyz defines

We replace the use of SBI_STATE_xyz defines with SBI_HSM_STATE_xyz
defines because the HSM state defines are complete enough to implement
HSM state machine in OpenSBI. As a result of this, we can now remove
sbi_hsm_hart_state_to_status() function because it is now redundant
and sbi_hsm_hart_get_state() can directly return HSM state or error.

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