dt-bindings: arm: stm32: Add SCMI version of STM32 boards (DK1/DK2/ED1/EV1)

Add a "secure" version based on SCMI of STM32 boards. Only boards
provided by STMicroelectronics are concerned:

-STM32MP157A-DK1
-STM32MP157C-DK2
-STM32MP157C-ED1
-STM32MP157C-EV1
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>
Acked-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/arm/stm32/stm32.yaml

@@ -75,6 +75,23 @@ properties:
           - const: st,stm32mp157
 
       - items:
+          - const: st,stm32mp157a-dk1-scmi
+          - const: st,stm32mp157a-dk1
+          - const: st,stm32mp157
+      - items:
+          - const: st,stm32mp157c-dk2-scmi
+          - const: st,stm32mp157c-dk2
+          - const: st,stm32mp157
+      - items:
+          - const: st,stm32mp157c-ed1-scmi
+          - const: st,stm32mp157c-ed1
+          - const: st,stm32mp157
+      - items:
+          - const: st,stm32mp157c-ev1
+          - const: st,stm32mp157c-ed1
+          - const: st,stm32mp157
+      - items:
+          - const: st,stm32mp157c-ev1-scmi
           - const: st,stm32mp157c-ev1
           - const: st,stm32mp157c-ed1
           - const: st,stm32mp157