include: sbi: Upgrade SBI implementation version to v0.3

The OpenSBI SBI implementation is now compliant with latest draft
SBI v0.3 specification so let's upgrade SBI implementation version.

This will also help HSM suspend function detection in S-mode because
HSM suspend function is only present when HSM extension is present
and SBI implementation version is 0.3 (or higher).

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