The unit for TPDM DSB element size is bits. So rename the property:
	qcom,dsb-element-size => qcom,dsb-element-bits
This also makes it consistent with the naming for the CMB element
size property.

There is no tpdm node in any DT as of now. Make this change before
any tpdm node is added to DT.

Fixes: 2a8d9b37 ("dt-bindings: arm: Add support for DSB element size")
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240218094322.22470-2-quic_jinlmao@quicinc.com
[ Reworded commit description to explain why we change this ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>