dt-bindings: display: meson-vpu: fix indentation of reg-names' "items"

Use two spaces for indentation instead of one to be consistent with the
rest of the file. No functional changes.

Fixes: 6b9ebf1e0e ("dt-bindings: display: amlogic, meson-vpu: convert to yaml")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/display/amlogic,meson-vpu.yaml

@@ -71,9 +71,9 @@ properties:
     maxItems: 2
 
   reg-names:
-   items:
-     - const: vpu
-     - const: hhi
+    items:
+      - const: vpu
+      - const: hhi
 
   interrupts:
     maxItems: 1