PM: dpm_watchdog: add module param to backtrace all CPUs

PM: dpm_watchdog: add module param to backtrace all CPUs

Add dpm_watchdog_all_cpu_backtrace module parameter which
controls all CPU backtrace dump before the DPM watchdog panics
the system.

This is expected to help understand what might have caused device
timeout.

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Link: https://patch.msgid.link/20251007063551.3147937-1-senozhatsky@chromium.org
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>