dt-bindings: soc: mediatek: dvfsrc: Add support for MT6893

dt-bindings: soc: mediatek: dvfsrc: Add support for MT6893

Add a compatible for the MediaTek Dimensity 1200 (MT6893) SoC's
DVFSRC hardware, introducing capability to communicate with it.

Even though this SoC uses the same basic version of the DVFSRC
IP as MT8195, the vcore-vdram parameters are different, hence
no fallback compatibility is possible.

Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20250410144019.475930-2-angelogioacchino.delregno@collabora.com
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>