wifi: iwlwifi: queue: move iwl_txq_gen2_set_tb() up

We need this earlier in the file next, move it up to have
an easier to read change, since this moves other things
in the diff git generates by default.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230816104355.c6d798b600bb.I9b891ee3d3dc67822a28e44941409f5b7cb637cf@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>