IB/hns: Fix mispelling of subsystem

s/wubsytem/subsystem/

Link: https://lore.kernel.org/r/20210322022751.4137205-1-unixbhaskar@gmail.comSigned-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Documentation/devicetree/bindings/infiniband/hisilicon-hns-roce.txt

 Hisilicon RoCE DT description
 
 Hisilicon RoCE engine is a part of network subsystem.
-It works depending on other part of network wubsytem, such as, gmac and
+It works depending on other part of network subsystem, such as gmac and
 dsa fabric.
 
 Additional properties are described here: