dt-bindings: soc: ti: pruss: Add documentation for PA_STATS support

Add documentation for pa-stats node which is syscon regmap for
PA_STATS registers. This will be used to dump statistics maintained by
ICSSG firmware.

Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-by: Roger Quadros <[e-mail]>
Acked-by: Nishanth Menon <[e-mail]>
Signed-off-by: MD Danish Anwar <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

Documentation/devicetree/bindings/soc/ti/ti,pruss.yaml

···
 
     additionalProperties: false
 
+  ^pa-stats@[a-f0-9]+$:
+    description: |
+      PA-STATS sub-module represented as a SysCon. PA_STATS is a set of
+      registers where different statistics related to ICSSG, are dumped by
+      ICSSG firmware. This syscon sub-module will help the device to
+      access/read/write those statistics.
+
+    type: object
+
+    additionalProperties: false
+
+    properties:
+      compatible:
+        items:
+          - const: ti,pruss-pa-st
+          - const: syscon
+
+      reg:
+        maxItems: 1
+
   interrupt-controller@[a-f0-9]+$:
     description: |
       PRUSS INTC Node. Each PRUSS has a single interrupt controller instance