spi: dt-bindings: spi-controller: remove unnecessary 'maxItems: 1' from reg

Mixing array constraints like 'maxItems' and string or integer value
constraints like 'minimum' don't make sense. Also, with only value
constraints, it is implied we have a single value. So lets remove
'maxItems: 1'.

Cc: Mark Brown <[email protected]>
Cc: [email protected]
Signed-off-by: Rob Herring <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

Author: robherring

Documentation/devicetree/bindings/spi/spi-controller.yaml

@@ -73,7 +73,6 @@ patternProperties:
           Compatible of the SPI device.
 
       reg:
-        maxItems: 1
         minimum: 0
         maximum: 256
         description: