net: ipa: kill ipa_power_modem_queue_stop()

All ipa_power_modem_queue_stop() does now is call netif_stop_queue().
Just call netif_stop_queue() in the one place it's needed, and get
rid of ipa_power_modem_queue_stop().

Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20240130192305.250915-6-elder@linaro.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>