drivers: serial: stm32: Implement PM_DEVICE mode support

Implement PM_DEVICE support and treatment of _pm_action hook.

(cherry picked from commit a439c04eb4da6f880685abe37433618df134b4dc)

Original-Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>
GitOrigin-RevId: a439c04eb4da6f880685abe37433618df134b4dc
Change-Id: I4d2803a789a2b6eeb134ca814fa4e544ae7d2999
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/3829402
Tested-by: CopyBot Service Account <copybot.service@gmail.com>
Commit-Queue: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
1 file changed