IB/core: Do not set the gid type when reserving default entries

When default GIDs are added, their gid type is set by
ib_cache_gid_set_default_gid().  There is no need to set the gid type of a
free GID entry during GID table initialization.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>