libertas: support mesh for various firmware versions

CMD_MESH_CONFIG command ID and a couple of structure members in TxPD,
RxPD have been changed in firmware version 10.x.y.z and newer.

Signed-off-by: Kiran Divekar <dkiran@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>