IB/core: Refer to RoCE port property to decide building cache

IB/core: Refer to RoCE port property to decide building cache

IB core maintains the GID cache entries for the GID table.
This cache table has to be maintained regardless of HCA's
support of GID table.
For IB and iWarp ports, cache is created by querying the HCA.
For RoCE cache is created based on netdev events.

Therefore just refer to the RoCE port property of the {device, port} to
decide whether to build cache by querying HCA or from netdev events.
There is no need to check if HCA support GID table or not.

ib_cache_update() referred to RoCE attribute before validating
port. Though in all current callers port is valid, it is incorrect
to query RoCE port property before validating the port. Therefore,
rdma_protocol_roce() check is done after rdma_is_port_valid() verifies
that port is valid.

Fixes: 115b68aa6ea4 ("IB/ocrdma: Removed GID add/del null routines")
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>