[i-g-t,v2] tests/kms_async_flips: Skip Async flips on joiner output

[Joshi, Kunal1]

On 24-10-2024 16:41, Santhosh Reddy Guddati wrote:
> Async flips are disallowed with joiner, but the test commit still
> goes through and causes failures. Update the tests to skip on
> joiner outputs.
>
> V2: Skip tests only on joiner outputs (Kunal).
>
> Signed-off-by: Santhosh Reddy Guddati <santhosh.reddy.guddati at intel.com>
Reviewed-by: Kunal Joshi <kunal1.joshi at intel.com>