Add compatibility to Arm Morello System Development Platform.

Note: Morello is at the same time the name of an Architecture [1], an SoC
[2] and a Board [2].
To distinguish in between Architecture/SoC and Board we refer to the first
as arm,morello and to the second as arm,morello-sdp.

[1] https://developer.arm.com/Architectures/Morello
[2] https://www.morello-project.org/

Cc: Linus Walleij <redacted>
Cc: Rob Herring <robh@kernel.org>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Sudeep Holla <redacted>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 Documentation/devicetree/bindings/arm/arm,vexpress-juno.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/arm,vexpress-juno.yaml b/Documentation/devicetree/bindings/arm/arm,vexpress-juno.yaml
index 8dd6b6446394..7934d2c4cba0 100644
--- a/Documentation/devicetree/bindings/arm/arm,vexpress-juno.yaml
+++ b/Documentation/devicetree/bindings/arm/arm,vexpress-juno.yaml

@@ -118,6 +118,9 @@ properties:
         items:
           - const: arm,foundation-aarch64
           - const: arm,vexpress
+      - description: Arm Morello System Development Platform
+        items:
+          - const: arm,morello-sdp