dt-bindings: soc: ti: k3-ringacc: Describe cfg reg region

RINGACC module on K3 SoCs have CFG register region which is usually
configured by a Device Management firmware. But certain entities such as
bootloader (like U-Boot) may have to access them directly. Describe this
region in the binding documentation for completeness of module
description.

Keep the binding compatible with existing DTS files by requiring first
four regions to be present at least.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230809175932.2553156-2-vigneshr@ti.com
Signed-off-by: Nishanth Menon <nm@ti.com>

Documentation/devicetree/bindings/soc/ti/k3-ringacc.yaml

@@ -34,18 +34,22 @@ properties:
       - const: ti,am654-navss-ringacc
 
   reg:
+    minItems: 4
     items:
       - description: real time registers regions
       - description: fifos registers regions
       - description: proxy gcfg registers regions
       - description: proxy target registers regions
+      - description: configuration registers region
 
   reg-names:
+    minItems: 4
     items:
       - const: rt
       - const: fifos
       - const: proxy_gcfg
       - const: proxy_target
+      - const: cfg
 
   msi-parent: true
 
@@ -80,8 +84,9 @@ examples:
             reg = <0x0 0x3c000000 0x0 0x400000>,
                   <0x0 0x38000000 0x0 0x400000>,
                   <0x0 0x31120000 0x0 0x100>,
-                  <0x0 0x33000000 0x0 0x40000>;
-            reg-names = "rt", "fifos", "proxy_gcfg", "proxy_target";
+                  <0x0 0x33000000 0x0 0x40000>,
+                  <0x0 0x31080000 0x0 0x40000>;
+                  reg-names = "rt", "fifos", "proxy_gcfg", "proxy_target", "cfg";
             ti,num-rings = <818>;
             ti,sci-rm-range-gp-rings = <0x2>; /* GP ring range */
             ti,sci = <&dmsc>;