dt-bindings: arm: Add missing root node constraint for board/SoC bindings

Board/SoC top-level compatible bindings should be constrained to the root
node. Add the missing constraints that the node name must be "/".

Cc: Baruch Siach <baruch@tkos.co.il>
Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Krzysztof Halasa <khalasa@piap.pl>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Anders Berg <anders.berg@lsi.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Alexandre TORGUE <alexandre.torgue@st.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20201001200943.1193870-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/arm/actions.yaml

@@ -11,6 +11,8 @@ maintainers:
   - Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
 
 properties:
+  $nodename:
+    const: "/"
   compatible:
     oneOf:
       # The Actions Semi S500 is a quad-core ARM Cortex-A9 SoC.

Documentation/devicetree/bindings/arm/altera.yaml

@@ -10,6 +10,8 @@ maintainers:
   - Dinh Nguyen <dinguyen@kernel.org>
 
 properties:
+  $nodename:
+    const: "/"
   compatible:
     items:
       - enum:

Documentation/devicetree/bindings/arm/axxia.yaml

@@ -10,6 +10,8 @@ maintainers:
   - Anders Berg <anders.berg@lsi.com>
 
 properties:
+  $nodename:
+    const: "/"
   compatible:
     description: LSI AXM5516 Validation board (Amarillo)
     items:

Documentation/devicetree/bindings/arm/bitmain.yaml

@@ -10,6 +10,8 @@ maintainers:
   - Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
 
 properties:
+  $nodename:
+    const: "/"
   compatible:
     items:
       - enum:

Documentation/devicetree/bindings/arm/digicolor.yaml

@@ -10,6 +10,8 @@ maintainers:
   - Baruch Siach <baruch@tkos.co.il>
 
 properties:
+  $nodename:
+    const: "/"
   compatible:
     const: cnxt,cx92755
 

Documentation/devicetree/bindings/arm/intel-ixp4xx.yaml

@@ -10,6 +10,8 @@ maintainers:
   - Linus Walleij <linus.walleij@linaro.org>
 
 properties:
+  $nodename:
+    const: "/"
   compatible:
     oneOf:
       - items:

Documentation/devicetree/bindings/arm/qcom.yaml

@@ -73,6 +73,8 @@ description: |
   foundry 2.
 
 properties:
+  $nodename:
+    const: "/"
   compatible:
     oneOf:
       - items:

Documentation/devicetree/bindings/arm/rda.yaml

@@ -10,6 +10,8 @@ maintainers:
   - Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
 
 properties:
+  $nodename:
+    const: "/"
   compatible:
     items:
       - enum:

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

@@ -10,6 +10,8 @@ maintainers:
   - Alexandre Torgue <alexandre.torgue@st.com>
 
 properties:
+  $nodename:
+    const: "/"
   compatible:
     oneOf:
       - items:

Documentation/devicetree/bindings/arm/tegra.yaml

@@ -11,6 +11,8 @@ maintainers:
   - Jonathan Hunter <jonathanh@nvidia.com>
 
 properties:
+  $nodename:
+    const: "/"
   compatible:
     oneOf:
       - items: