dt-bindings: crypto: Let STM32 define Ux500 HASH

This adds device tree bindings for the Ux500 HASH block
as a compatible in the STM32 HASH bindings.

The Ux500 HASH binding has been used for ages in the kernel
device tree for Ux500 but was never documented, so fill in
the gap by making it a sibling of the STM32 HASH block,
which is what it is.

The relationship to the existing STM32 HASH block is pretty
obvious when looking at the register map, and I have written
patches to reuse the STM32 HASH driver on the Ux500.

The main difference from the outside is that the Ux500 HASH
lacks the interrupt line, so some special if-clauses are
needed to accomodate this in the binding.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Documentation/devicetree/bindings/crypto/st,stm32-hash.yaml

@@ -6,12 +6,18 @@ $schema: http://devicetree.org/meta-schemas/core.yaml#
 
 title: STMicroelectronics STM32 HASH
 
+description: The STM32 HASH block is built on the HASH block found in
+  the STn8820 SoC introduced in 2007, and subsequently used in the U8500
+  SoC in 2010.
+
 maintainers:
   - Lionel Debieve <lionel.debieve@foss.st.com>
 
 properties:
   compatible:
     enum:
+      - st,stn8820-hash
+      - stericsson,ux500-hash
       - st,stm32f456-hash
       - st,stm32f756-hash
 
@@ -41,11 +47,26 @@ properties:
     maximum: 2
     default: 0
 
+  power-domains:
+    maxItems: 1
+
 required:
   - compatible
   - reg
   - clocks
-  - interrupts
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          items:
+            const: stericsson,ux500-hash
+    then:
+      properties:
+        interrupts: false
+    else:
+      required:
+        - interrupts
 
 additionalProperties: false