dt-bindings: phy: mediatek: tphy: support software efuse load

Add optional property nvmem-cells and nvmem-cell-names to support
software efuse load, this helps to fix the efuse bit shift issue
on mt8195 etc.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20211218082802.5256-1-chunfeng.yun@mediatek.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>