dt-bindings: soc: qcom,wcnss: fix bluetooth address example

The 'local-bd-address' property is used to pass a unique Bluetooth
device address from the boot firmware to the kernel and should otherwise
be left unset.

Update the example to reduce the risk that a non-zero address will be
used by default in some devicetree.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240501075005.4588-1-johan+linaro@kernel.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>