RDMA: Use default_groups in kobj_type

There are currently 2 ways to create a set of sysfs files for a kobj_type,
through the default_attrs field, and the default_groups field.  Move the
IB code to use default_groups field which has been the preferred way since
commit aa30f47c ("kobject: Add support for default attribute groups to
kobj_type") so that we can soon get rid of the obsolete default_attrs
field.

Link: https://lore.kernel.org/r/20220103152259.531034-1-gregkh@linuxfoundation.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>