UPSTREAM: PM: sleep: Allow configuring the DPM watchdog to warn earlier than panic

Allow configuring the DPM watchdog to warn about slow suspend/resume
functions without causing a system panic(). This allows you to set the
DPM_WATCHDOG_WARNING_TIMEOUT to something like 5 or 10 seconds to get
warnings about slow suspend/resume functions that eventually succeed.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Link: https://patch.msgid.link/20250109125957.v2.1.I4554f931b8da97948f308ecc651b124338ee9603@changeid


[ rjw: Subject edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit 56cabb93)

BUG=b:382269699
TEST=Fake a short hang and see warning but no panic

Change-Id: I4554f931b8da97948f308ecc651b124338ee9603
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/6191528


Reviewed-by: Sean Paul <sean@poorly.run>
Tested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Reviewed-by: Boris Mittelberg <bmbm@google.com>
Commit-Queue: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Hubert Mazur <hmazur@google.com>