net/sched: move struct tc_mqprio_qopt_offload from pkt_cls.h to pkt_sched.h

Since mqprio is a scheduler and not a classifier, move its offload
structure to pkt_sched.h, where struct tc_taprio_qopt_offload also lies.

Also update some header inclusions in drivers that access this
structure, to the best of my abilities.

Cc: Igor Russkikh <irusskikh@marvell.com>
Cc: Yisen Zhuang <yisen.zhuang@huawei.com>
Cc: Salil Mehta <salil.mehta@huawei.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Tony Nguyen <anthony.l.nguyen@intel.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Saeed Mahameed <saeedm@nvidia.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Horatiu Vultur <horatiu.vultur@microchip.com>
Cc: Lars Povlsen <lars.povlsen@microchip.com>
Cc: Steen Hegelund <Steen.Hegelund@microchip.com>
Cc: Daniel Machon <daniel.machon@microchip.com>
Cc: UNGLinuxDriver@microchip.com
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>