dt-bindings: gpu: samsung-rotator: Add missing properties

Add common properties appearing in DTSes (iommus, power-domains) to fix dtbs_check warnings like:

arch/arm/boot/dts/exynos4210-i9100.dt.yaml: rotator@12810000:
'iommus', 'power-domains' do not match any of the regexes: 'pinctrl-[0-9]+'

---

Changes since v2:
1. Add maxItems to power domains and iommus

Changes since v1:
1. Add properties instead of using unevaluated

---
 Documentation/devicetree/bindings/gpu/samsung-rotator.yaml | 6 ++++++
 1 file changed, 6 insertions(+)

index 665c6e3b31d3..62486f55177d 100644
@@ -22,6 +22,12 @@ properties:
   interrupts:
     maxItems: 1
 
+  iommus:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
   clocks:
     maxItems: 1
 

2.17.1

Applied, thanks!