dt-bindings: soc: qcom: stats: Add compatible for Shikra

SoC LPM stats are present in RPM MSGRAM and subsystem LPM stats are present
in SMEM for Shikra.

A generic "qcom,rpm-stats" compatible only reads SoC LPM stats like vmin
and vlow.

Document shikra rpm compatible to read subsystem LPM stats too along with
SoC LPM stats.

Keep "qcom,rpm-stats" as a fallback for RPM targets, so that SoC level
stats are still shown even without subsystem level stats support. A plain
enum can't express that, since it caps compatible at one item. Add a oneOf
branch with items for this pattern.

Signed-off-by: Sneh Mankad <sneh.mankad@oss.qualcomm.com>
Reviewed-by: Komal Bajaj <komal.bajaj@oss.qualcomm.com>
Link: https://patch.msgid.link/20260907-shikra_stats-v4-1-3825351f9740@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

Documentation/devicetree/bindings/soc/qcom/qcom-stats.yaml

@@ -18,15 +18,22 @@ description:
 
 properties:
   compatible:
-    enum:
-      - qcom,rpmh-stats
-      - qcom,sdm845-rpmh-stats
-      - qcom,rpm-stats
-      # For older RPM firmware versions with fixed offset for the sleep stats
-      - qcom,apq8084-rpm-stats
-      - qcom,msm8226-rpm-stats
-      - qcom,msm8916-rpm-stats
-      - qcom,msm8974-rpm-stats
+    oneOf:
+      - enum:
+          - qcom,rpmh-stats
+          - qcom,sdm845-rpmh-stats
+          - qcom,rpm-stats
+          # For older RPM firmware versions with fixed offset for the sleep stats
+          - qcom,apq8084-rpm-stats
+          - qcom,msm8226-rpm-stats
+          - qcom,msm8916-rpm-stats
+          - qcom,msm8974-rpm-stats
+      # SoC-specific compatibles that also read subsystem-level stats,
+      # falling back to "qcom,rpm-stats" for SoC-level stats only
+      - items:
+          - enum:
+              - qcom,shikra-rpm-stats
+          - const: qcom,rpm-stats
 
   reg:
     maxItems: 1