forked from Mirrors/opensbi

Since event support will be checked in the next commits, return a value from sse_event_get() to allow propagating it. This will be used to report SBI_ERR_NOT_SUPPORTED when an event isn't supported. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Atish Patra <atishp@rivosinc.com>