dt-bindings: serial: stm32: add power-domains property

STM32 serial may be in a power domain.
Allow a single 'power-domains' entry for STM32 serial devices.

Signed-off-by: Valentin Caron <[email protected]>
Acked-by: Conor Dooley <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: VCASTM

Documentation/devicetree/bindings/serial/st,stm32-uart.yaml

@@ -58,6 +58,9 @@ properties:
 
   wakeup-source: true
 
+  power-domains:
+    maxItems: 1
+
   rx-threshold:
     description:
       If value is set to 1, RX FIFO threshold is disabled.