arm64: dts: hisi: fix hip06 sas am-max-trans quirk

The string for the am max transmissions quirk property
is not correct -> fix it.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>