FROMGIT: net: ipa: kill gsi_channel_freeze() and gsi_channel_thaw()

Open-code gsi_channel_freeze() and gsi_channel_thaw() in all callers
and get rid of these two functions.  This is part of reworking the
sequence of things done during channel suspend/resume and start/stop.

Signed-off-by: Alex Elder <elder@linaro.org>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
(cherry picked from commit bd1ea1e4
 https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git

 master)

BUG=b:177097776
TEST=Modem functional, No IPA hang in suspend stress test

Signed-off-by: Sujit Kautkar <sujitka@chromium.org>
Change-Id: I723f72f67ad5a16a6ea17cf5317f9338364deabf
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/2674467


Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/2685030