UPSTREAM: dt-bindings: sram: Document reg-io-width property

Some SRAMs need to be accessed with a specific access width, define
the 'reg-io-width' property specifying such access sizes.

Bug: 413610810
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Change-Id: If294e228e6c5f5bc3126e8fdd55f735a5b1ce915
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Message-Id: <20240827182450.3608307-2-florian.fainelli@broadcom.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
(cherry picked from commit 14b2157a9c14481c3b967d8d1a95972bf885fb88)
Signed-off-by: Danesh Petigara <danesh.petigara@broadcom.com>
Signed-off-by: Pierre Couillaud <pierre@broadcom.com>

Documentation/devicetree/bindings/sram/sram.yaml

@@ -101,6 +101,12 @@ patternProperties:
           IO mem address range, relative to the SRAM range.
         maxItems: 1
 
+      reg-io-width:
+        description:
+          The size (in bytes) of the IO accesses that should be performed on the
+          SRAM.
+        enum: [1, 2, 4, 8]
+
       pool:
         description:
           Indicates that the particular reserved SRAM area is addressable