platform/mellanox: tmfifo: fix kernel-doc warnings

Fix kernel-doc notation for structs and struct members to prevent
these warnings:

mlxbf-tmfifo.c:73: warning: cannot understand function prototype: 'struct mlxbf_tmfifo_vring '
mlxbf-tmfifo.c:128: warning: cannot understand function prototype: 'struct mlxbf_tmfifo_vdev '
mlxbf-tmfifo.c:146: warning: cannot understand function prototype: 'struct mlxbf_tmfifo_irq_info '
mlxbf-tmfifo.c:158: warning: cannot understand function prototype: 'struct mlxbf_tmfifo_io '
mlxbf-tmfifo.c:182: warning: cannot understand function prototype: 'struct mlxbf_tmfifo '
mlxbf-tmfifo.c:208: warning: cannot understand function prototype: 'struct mlxbf_tmfifo_msg_hdr '
mlxbf-tmfifo.c:138: warning: Function parameter or member 'config' not described in 'mlxbf_tmfifo_vdev'
mlxbf-tmfifo.c:212: warning: Function parameter or member 'unused' not described in 'mlxbf_tmfifo_msg_hdr'

Fixes: 1357dfd7 ("platform/mellanox: Add TmFifo driver for Mellanox BlueField Soc")
Fixes: bc05ea63

 ("platform/mellanox: Add BlueField-3 support in the tmfifo driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: lore.kernel.org/r/202309252330.saRU491h-lkp@intel.com
Cc: Liming Sun <lsun@mellanox.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: Mark Gross <markgross@kernel.org>
Cc: Vadim Pasternak <vadimp@nvidia.com>
Cc: platform-driver-x86@vger.kernel.org
Link: https://lore.kernel.org/r/20230926054013.11450-1-rdunlap@infradead.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>