dt-bindings: Fix 'reg' size issues in zynqmp examples

The default sizes in examples for 'reg' are 1 cell each. Fix the
incorrect sizes in zynqmp examples:

Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dpdma.example.dt.yaml: example-0: dma-controller@fd4c0000:reg:0: [0, 4249616384, 0, 4096] is too long
	From schema: /usr/local/lib/python3.8/dist-packages/dtschema/schemas/reg.yaml
Documentation/devicetree/bindings/display/xlnx/xlnx,zynqmp-dpsub.example.dt.yaml: example-0: display@fd4a0000:reg:0: [0, 4249485312, 0, 4096] is too long
	From schema: /usr/local/lib/python3.8/dist-packages/dtschema/schemas/reg.yaml
Documentation/devicetree/bindings/display/xlnx/xlnx,zynqmp-dpsub.example.dt.yaml: example-0: display@fd4a0000:reg:1: [0, 4249526272, 0, 4096] is too long
	From schema: /usr/local/lib/python3.8/dist-packages/dtschema/schemas/reg.yaml
Documentation/devicetree/bindings/display/xlnx/xlnx,zynqmp-dpsub.example.dt.yaml: example-0: display@fd4a0000:reg:2: [0, 4249530368, 0, 4096] is too long
	From schema: /usr/local/lib/python3.8/dist-packages/dtschema/schemas/reg.yaml
Documentation/devicetree/bindings/display/xlnx/xlnx,zynqmp-dpsub.example.dt.yaml: example-0: display@fd4a0000:reg:3: [0, 4249534464, 0, 4096] is too long
	From schema: /usr/local/lib/python3.8/dist-packages/dtschema/schemas/reg.yaml

Cc: Hyun Kwon <hyun.kwon@xilinx.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: dri-devel@lists.freedesktop.org
Cc: dmaengine@vger.kernel.org
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Rob Herring <robh@kernel.org>