dt-bindings: soc: update MT2712 power dt-bindings

Add new power domains(MFG_SC1/MFG_SC2/MFG_SC3)
for MT2712 according to ECO design change.

Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>