dt-bindings: samsung: pmu: Document Exynos850

Exynos850 SoC can reuse PMU driver functionality. Add corresponding
compatible string to PMU bindings documentation.
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211028144313.9444-1-semen.protsenko@linaro.orgSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

Documentation/devicetree/bindings/arm/samsung/pmu.yaml

@@ -24,6 +24,7 @@ select:
           - samsung,exynos5420-pmu
           - samsung,exynos5433-pmu
           - samsung,exynos7-pmu
+          - samsung,exynos850-pmu
           - samsung-s5pv210-pmu
   required:
     - compatible
@@ -41,6 +42,7 @@ properties:
           - samsung,exynos5420-pmu
           - samsung,exynos5433-pmu
           - samsung,exynos7-pmu
+          - samsung,exynos850-pmu
           - samsung-s5pv210-pmu
       - const: syscon