net: ipa: kill the IPA power STOPPED flag

net: ipa: kill the IPA power STOPPED flag

Currently the STOPPED IPA power flag is used to indicate that the
transmit queue has been stopped.  Previously this was used to avoid
setting the STARTED flag unless the queue had already been stopped.
It meant transmit queuing would be enabled on resume if it was
stopped by the transmit path--and if so, it ensured it only got
enabled once.

We only stop the transmit queue in the transmit path.  The STARTED
flag has been removed, and it causes no real harm to enable
transmits when they're already enabled.  So we can get rid of
the STOPPED flag and call netif_wake_queue() unconditionally.

This makes the IPA power spinlock unnecessary, so it can be removed
as well.

Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20240130192305.250915-5-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>