samples: boards: stm32: Add a serial wakeup sample

Add a sample to demonstrate use of (LP)U(S)ART with wakeup capability
This sample is provided with 2 configurations
- nucleo_wb55rg: Basic configuration that could be exercised in CI
- stm32l562e_dk: "Full feature" configuration that require some set up
configuration (be able to display console from lpuart) and allows to
achieve lowest power consumption.

(cherry picked from commit f5378424f7f492a8ae0d173a015bc1186fcc7127)

Original-Signed-off-by: Erwan Gouriou <>
GitOrigin-RevId: f5378424f7f492a8ae0d173a015bc1186fcc7127
Change-Id: I38acc413ca32f5d281c33b5b60ce56508a5c9df9
Commit-Queue: Jack Rosenthal <>
Tested-by: CopyBot Service Account <>
Reviewed-by: Jack Rosenthal <>
diff --git a/src/third_party/zephyr/main b/src/third_party/zephyr/main
index 9fffdf7..81dd14e 160000
--- a/src/third_party/zephyr/main
+++ b/src/third_party/zephyr/main
@@ -1 +1 @@
-Subproject commit 9fffdf7c5d6a830a171b7a0d20f8a72730d47cf5
+Subproject commit 81dd14e9e04c681ef03d361a6e697d1753fa2055