dt-bindings: display: ti: Fix dtc unit-address warnings in examples

dt-bindings: display: ti: Fix dtc unit-address warnings in examples

Extra dtc warnings (roughly what W=1 enables) are now enabled by default
when building the binding examples. These were fixed treewide in
5.6-rc5, but some new display bindings have been added with new
warnings:

Documentation/devicetree/bindings/display/ti/ti,am65x-dss.example.dts:21.27-49.11: Warning (unit_address_format): /example-0/dss@04a00000: unit name should not have leading 0s
Documentation/devicetree/bindings/display/ti/ti,j721e-dss.example.dts:21.27-72.11: Warning (unit_address_format): /example-0/dss@04a00000: unit name should not have leading 0s
Documentation/devicetree/bindings/display/ti/ti,k2g-dss.example.dts:20.27-42.11: Warning (unit_address_format): /example-0/dss@02540000: unit name should not have leading 0s

Cc: Jyri Sarha <jsarha@ti.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Jyri Sarha <jsarha@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200313180727.23044-1-robh@kernel.org