ice: reorder disabling IRQ and NAPI in ice_qp_dis

ice_qp_dis() currently does things in very mixed way. Tx is stopped
before disabling IRQ on related queue vector, then it takes care of
disabling Rx and finally NAPI is disabled.

Let us start with disabling IRQs in the first place followed by turning
off NAPI. Then it is safe to handle queues.

One subtle change on top of that is that even though ice_qp_ena() looks
more sane, clear ICE_CFG_BUSY as the last thing there.

Fixes: 2d4238f5

 ("ice: Add support for AF_XDP")
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Chandan Kumar Rout <chandanx.rout@intel.com> (A Contingent Worker at Intel)
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>