net: wwan: iosm: set tx queue len

Set wwan net dev tx queue len to DEFAULT_TX_QUEUE_LEN.

Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Reviewed-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>